It's fully-updated Chromium. If that doesn't work then sod it.

It doesn't look like any ICC profile will do any good here. I may have run out of options to fix this model so that it will print colours OK. Bugger.

This link to cityinkexpress.co.uk will help explain what ICC Profiles are normally used by print shops to achieve.

In a nutshell, the biggest problem for a printshop is when a customer's home-produced printout on *their* printer looks lovely in their business/home, and all wrong from the Print Shop. So, City Ink Express provide a Colour Chart for the customer to printout using their printer. The customer then posts (or delivers) the printout back to the shop. City Ink Express have a piece of software ("advanced color calibration software") that scans the printout & produces an ICC Profile (software file) which is emailed back to the customer. The intention of the profile is to shift colour differences between the customer's printer & the commercial printer, so that (as much as possible) the commercial printout looks as close to the home printout as possible. The main issue for me is that no details of how that profile is used are revealed.

You can probably see why the above excited me re: my problem, and specifically because I had seen references to "Profile" whilst printing. Nope, wrong kind of Profile.

Brother has a Printing Profile, but you can tell from the link that it is nothing to do with shifting colour balances.

"ICC Profiles" feature exactly nowhere in brother.com. What *does* feature is "Windows ICM Profiles". That link states that these are provided on the driver CD at "x:\driver\ps\icm". Not on the CD for the DPL3510CDW they arn't. Yet another blind alley.

The final blind alley was me trawling through all the MSI files on the CD yet again, this time looking for "Profiles". Or even "ICC" or "ICM". Just in case. Nope. None. Nada.

I've also tried to find an address at which to report the Dead Fish that is the CUPS driver for the DPL3510CDW. I found a Reporting Issues information page. The one missing item was either an email address, a website page, a telephone number or even the location of a stone in a park to place the secret paper underneath. It seems like they don't want to know.

And with that final big NO I must leave this report.

Where's the NOT SOLVED button?

(re: ICC_Profile_Creator)

Well, that looks awesome (hurrah)
Ah, it is integrated into rawtherapee (boo)
But rawtherapee is open-source (hurrah)
The AppImage is 108 MB (boo)

Bugger. And I strongly suspect that the profile created is directly related to the screen (meaning, do colours from *any* program show accurately on the screen). I've already got & use a profile for that (and it isn't even a high-performance screen).

Still, no matter. That was a superb find. I now need to find whether the Profile-Maker can be installed independently of the entire program†, and whether that can be used for a printer. I'm also shortly going to trawl through the Brother win-drivers again looking for a profile. I also need to find the way to communicate to CURL (which I think is also openprinting.com) that their current Brother DCP-L3510CDW PPD is pants, and to offer the derived-from-windows collection (69 separate files‡).

† Feb 6 update: I did check & the GitHub site shows a single file to create the utility. However, it is thoroughly integrated into the whole program, with dozens of calls to other sections
‡ Feb 6 update: 35 PPD files after removing dupes

I certainly agree with the (non-existent) Profile file as being a likely source for the problem. That was my early suss when first trying to fix this beast. The fact that there is less problems with the CMYK driver than the RGB driver points in the same direction (as far as I understand these things). However, how do I get such a file? I managed to get one for my monitor from an old Windows driver, but that was a Monocoque, so there was only one place to look.

@delgado:
The Brother is 600dpi and generally colours are good (recall that it is CMYK, same as printing inks). They are simply wrong!

The OP detailed my problem; in a nutshell:

• Having paid out shed-loads of money to Amazon for a LED-powered printer/copier/scanner/wlan CMYK-toner network printer and,

• having downloaded an up-to-date Linux driver from the Brother website,

• discovered that it completely screwed up the colour balance in both text & photographs and,

• Brother just responded with handy-wavy gestures & did nuthin'

To rub salt into the wound, I saved a file that was giving print difficulties as a PDF, took it to a friend with a business, and used his HP DeskJet to print it out (flawless). Bah!

Very recently I discovered that the key to ALL printing (regardless of your OS) is a PPD file. These were originated by Apple (as I understand it), and Adobe is in there somewhere. They are plain-text configuration files for PostScript and, mostly, are to specify ways in which printer-specific services are to be configured, and how things differ from the defaults. Here is the CUPS Help file (link only works if you have CUPS installed):

The Printer Queue shows icons for each installed printer. CUPS uses a PPD file at install-time, in the process creating that icon(s):

Here is the head of each file so that you can get a handle on what they are like:

$ sudo head /etc/cups/ppd/BRPPL3510CDW-CMYK.ppd -n 40
*PPD-Adobe: "4.3"
*%================================================
*%	Copyright(C) 2017 Brother Industries, Ltd.
*%	"Brother DCP-L3510CDW BR-Script3"
*%================================================

*%==== General Information Keywords ========================
*FormatVersion: "4.3"
*FileVersion: "1.0"
*LanguageEncoding: ISOLatin1
*LanguageVersion: English
*Manufacturer: "Brother"
*PCFileName: "BRPPL3510CDW.PPD"
*Product: "(Brother DCP-L3510CDW)"
*PSVersion: "(3010.106) 3"
*ShortNickName: "Brother DCP-L3510CDW BR-Script3"
*ModelName: "Brother DCP-L3510CDW BR-Script3"
*NickName: "Brother DCP-L3510CDW BR-Script3"

*%==== Basic Device Capabilities =============
*LanguageLevel: "3"
*TTRasterizer: Type42
*ColorDevice: True
*DefaultColorSpace: CMYK
*FileSystem: True
*?FileSystem:"
save 
	/devname (%disk0%) def 
	/ret false def 
	0 1 7{ 
		devname exch 48 add 5 exch put 
		devname devstatus { 
			0 ne {/ret true def}if 
			pop pop pop pop pop pop pop 
		}if 
	}for 
	ret {(True)}{(False)} ifelse = flush 
restore 
" 
*End

$ sudo head /etc/cups/ppd/DCP3510W-RGB.ppd -n 40
*PPD-Adobe: "4.3"

*%================================================
*%	Copyright(C) 2018 Brother Industries, Ltd.
*%	"Brother DCP-L3510CDW for CUPS"
*%================================================ 

*%==== General Information Keywords ========================
*FormatVersion: "4.3"
*FileVersion: "4.0.9"
*LanguageVersion: English
*LanguageEncoding: ISOLatin1
*PCFileName: "DCP3510W.PPD"
*Manufacturer: "Brother"
*Product: "(DCP-L3510CDW)"
*1284DeviceID: "MFG:Brother;MDL:DCP-L3510CDW"
*cupsVersion: 1.4
*cupsManualCopies: false
*cupsFilter: "application/vnd.cups-postscript 0 brother_lpdwrapper_dcpl3510cdw"
*%cupsFilter: "application/vnd.cups-pdf 0 brother_lpdwrapper_dcpl3510cdw"
*cupsModelNumber: 5
*ModelName: "Brother DCP-L3510CDW"
*ShortNickName: "DCP-L3510CDW"
*NickName: "Brother DCP-L3510CDW CUPS"
*PSVersion: "(3010.106) 3"

*%==== Basic Device Capabilities =============
*LanguageLevel: "3"
*ColorDevice: True
*DefaultColorSpace: RGB
*FileSystem: False
*Throughput: "17"
*VariablePaperSize: False
*TTRasterizer: Type42
*FreeVM: "2700000"
*DefaultResolution: 600dpi
*%DefaultOutputOrder: Reverse

*%=== UI Constraints ==================================
*UIConstraints: "*BRInputSlot AutoSelect *BRMediaType Label"

So, first I had to find a PPD file that would actually work. That was simple, if fiddly, once I found it, and is detailed in the OP. I then hoped that simply replacing the file located in /etc/cups/ppd with the new file renamed-to-the-old would be sufficient but, naturally, that was a foolish hope. There is an actual install process to go through, and that will be detailed in the next post.

Don't do this with Chimaera:

W: Skipping acquire of configured file 'non-free-firmware/binary-amd64/Packages'
 as repository 'http://deb.devuan.org/merged chimaera InRelease'
 doesn't have the component 'non-free-firmware'
 (component misspelt in sources.list?)

Edit: reset since code is too stupid to wrap lines to the page

Sounds like port-80 is blocked for external traffic. But of course, that would mean that nf_tables (or something) is running.

Sorry, but cannot help. I was competent with the old firewall, but know nothing about the new one(s).

Did you copy-paste those errors? There is a syntax error in the 2nd (s/b '<control>O', or perhaps 'Ctrl-O', not '<constrol>O').

Hi Geoff 42

It must be some other feature of your system that is preventing install of that version. I have the precise same sources.list as you, yet and have the 2.31-13+deb11u4 version for libc6 (note that my system is AMD, not intel):

$ sudo apt-cache policy
(snip)
500 http://deb.devuan.org/devuan chimaera-proposed-updates/main amd64 Packages
     release v=4.0.0,o=Devuan,a=chimaera-proposed-updates,n=chimaera-proposed-updates,l=Devuan,c=main,b=amd64
     origin deb.devuan.org
(snip)
$ apt search libc6 | head -n 3

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

Sorting...
Full Text Search...
libc6/stable,now 2.31-13+deb11u4 amd64 [installed]

PS
I also wondered why that single line was different to all others in the wiki!

(update)
Realising that I made an error (the update you are talking of is 2.31-13+deb11u5, not u4) I changed the proposed-updates line to match all others, then re-ran the apt update that had already been ran 5 minutes before. The results were startling:

$ ~/.update
Hit:1 http://deb.devuan.org/merged chimaera InRelease
Hit:2 http://deb.devuan.org/merged chimaera-security InRelease
Hit:3 http://deb.devuan.org/merged chimaera-updates InRelease
Hit:4 https://josm.openstreetmap.de/apt alldist InRelease
Get:5 http://deb.devuan.org/merged chimaera-proposed-updates InRelease [26.6 kB]
Hit:6 http://deb.devuan.org/merged chimaera-backports InRelease
Get:7 http://deb.devuan.org/merged chimaera-proposed-updates/main amd64 Packages [70.3 kB]
Get:8 http://deb.devuan.org/merged chimaera-proposed-updates/main Translation-en [38.4 kB]
Get:9 http://deb.devuan.org/merged chimaera-proposed-updates/non-free Translation-en [10.9 kB]
Get:10 http://deb.devuan.org/merged chimaera-proposed-updates/contrib Translation-en [499 B]
Fetched 147 kB in 2s (94.0 kB/s)                          
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
10 packages can be upgraded. Run 'apt list --upgradable' to see them.
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 10 not upgraded.
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  libbluray2 libc-bin libc-dev-bin libc-l10n libc6 libc6-dev libc6-i386 locales shim-helpers-amd64-signed shim-unsigned
10 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
(snip)
$ apt search libc6 | head -n 3

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

Sorting...
Full Text Search...
libc6/stable-proposed-updates,now 2.31-13+deb11u5 amd64 [installed]

Wow! I've been missing out on a lot of updates. Thanks.

Ogis1975's is a reasonable question to ask.

If you get offended by the question then

1. That is the response of a child, not of a grown adult

2. No-one can ever then expect that you will take this matter seriously & responsibly

3. The future then will be filled with an infinite repetition of these (and other) issues, with zero fix in sight

Now yes, of course, you also get idiotic responses from entitled fools that have zero respect for the continual efforts of unpaid volunteers on their behalf. Those people do not deserve any respect, but that does not mean that Ogis1975's question is not a reasonable one to ask.

Many thanks to Ralph for his continual efforts on Devuan's behalf. It is a new venture & I fully expect bumps along the road. As long as things continually improve I have few complaints & immense gratitude for the simple fact that it is available to the world & to me.

I advise you most strongly not to bother.

This is the result of a youtube-dl (local) upgrade attempt just now:

sudo /usr/local/bin/youtube-dl -U
youtube-dl is up-to-date (2021.12.17)

It has been abandoned & no longer will download most YT videos. Use yt-dlp instead (available via backports):

man yt-dlp
NAME
       yt-dlp - A youtube-dl fork with additional features and patches
# …
$ yt-dlp --version
2022.08.19