Adding Custom Working Profiles

Hi Everyone,
Brand new to RT and impressed !
I am using Catalina 10.15.4 with RT 5.8
Specifically, I want to add a new custom Working Profile (DCam 3, J.Holmes.icc) in the Color Management Working Profile Section…no luck so far!
I am using a workingspaces.json file(page 335/336 of the RT manual) and putting it in MacintoshHD/Library/Colorsync/Profiles/Displays/.The same profile(Holmes), I can access as an Input Profile(Custom) in RT no problem and without the Json shell. I gather the profile needs to be dressed up in the Json shell for reading in the Working Spaces section.
In the Json script, I used “Aces” and “Acescg” as " name" and "name"in the script as I was uncertain what else I should do.
“file” : “/macintosh HD/library/Colorsync/Profiles/displays/DCam 3, J.Holmes.icc” successfully placed the Json file in the Mac OS Displays directory as Workingspaces.json .
I also included the matrixes for the Joseph Holmes profile in the Json file in the hope that the matrixes would do the trick if the name tags did not (page 336) but again no luck. One thing that I am sure of is that it is most likely my own inexperience that is at the root of the problem.

Any advice gratefully accepted,

And thanks for providing us with RT


@Keentolearn Welcome to the forum! Have you tried using the ICC Profile Creator within RT? The icon looks like this


It satisfies most of my needs. It also reveals where RT retrieves its profiles by where it saves. There is a directory for input and output profiles. I don’t have a mac so I can’t help you there.

If you have followed the custom working profiles RawPedia explanation, and if the json is on the right place (I can’t tell because I’m not a mac user), then the problem should be that you will have your profile shown as ACES.

In that example you’re really adding 2 new custom profiles: ACES and ACEScg.

In your case you should name your profile with the name you want, and point where the icc is located. Something like:

{"working_spaces": [
        "name" : "DCam3",
        "file" : "/path/to/DCam3.icc"

Thanks Xavier…will follow your instructions today and get back to you with results asap…thanks for such a prompt response…

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Hi Afre
Thanks for your reply.

Yes I did successfully use the RT profile maker to sign in Joseph Holmes color space as INPUT and Imageprint profiles as OUTPUT …no problem at all there…

The WORKING space profile however (as I’m sure you know) requires the use of a java type script…Json…for insertion of an additional color space in that working space area ( I use Holmes color spaces)

Xavier suggests renaming my profile (a copy of the Holmes profile) and inserting that name exclusively in the Json file…the difficulty for me was that I interpreted the demo example for a json file in the RT manual (pages 335/336) literally…two profile names were used…Aces and Aces cg …Aces for file info…Aces cg for matrix info…

I will be trying Xavier’s recommendation later today…it sounds right…will let you know.

Meanwhile thanks for your helpful advice…much appreciated…


Hi Xavier
Back again but the news isnt great…
Dressed up a new Json with a copy of the Holmes profile name clipped down to size, as you advised, from DCam 3 J.Holmes.icc to DCam3.icc and parked it exactly as you outlined in your Json suggestion template yesterday (and of course the Dcam3.icc is in the same folder )as follows:
“/Macintosh HD/Library/Colorsync/Profiles/Displays /”
The Finder in MacOS is able to open the Workingspaces.json file as I work on it in the BBeditor so I know there’s no connecton issues as I saw the BBedit going through on the workingspaces.json file as it happened.
Back then to RT and it just won’t accept and recognise the DCam3.icc as a Working Space in with the other 10 working spaces even though the command is in Json format…(Holmes is fine in the INPUT section). I wonder is the menu full up at 10 and won’t budge to include a no 11? …and don’t forget I’m saddled with Catalina (it has a lot of good points too).
Thanks for your interest

Hi, can you share the icc profile?

Well, I suggested, in fact.

Just in case, this is the updated contents of your workingspaces.json file. I understand the path you give is the absolute path to the icc profile and json file.

{"working_spaces": [
        "name" : "DCam3",
        "file" : "/Macintosh HD/Library/Colorsync/Profiles/Displays/DCam3.icc"

Please note how I have removed the space after Displays. Maybe it’s a typo, but again, just in case.

Ah, I have insomnia so I may have missed this. No, I don’t have experience adjusting the working space in RT. The reason is simple. I believe some modules rely on RT using the builtin one, but maybe that is no longer the case, as I don’t know the internals. I just know that RT does advanced LUT transforms to compensate for deficiencies in certain colour models. I wouldn’t want to mess around with that.

I don 't think he can. These are purchased items.

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I see. An alternative is to run RT in verbose mode (change Verbose to True in the options file) and paste the console output here – hopefully that gives a clue.

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Are you sure you don’t need to escape the space between “Macintosh” and “HD”?

Well, no, I’m not. As I said I’m not a mac user. I just copied/pasted the path given.

I didn’t thought about it because in Linux Mint (Ubuntu) you can have a path with spaces between words, and just by enclosing the full path between quotation marks it is accepted by a bash command.

Any mac user with more knowledge about it than me?

Hi Agriggio
Best thing might be to look up Joseph Holmes website ( you may know more about Joseph than I do)…His work is now recognised in ACR as a working space.
As you will understand I’m nervous that it may very well be copywrite and I would’nt feel comfortable in disclosing the Primaries without his sayso. But I may be wrong altogether.
Sorry I cant be more specific on that one.

Exact lines in the Json file as follows:{“working_spaces”:[
“name” : “DCam3”,
“file” :"/Macintosh HD/Library/Colorsync/Profiles/Displays/DCam3.icc"

I very much agree with you.
The Holmes Color Space is extremely advanced ,intelligent and flexible and was designed to fill gaps in the Color Space market as observed by Joseph Holmes himself many years ago.
I wouldn’t like to see any interference in the operation of the Holmes color space as it actually is. If that had to happen, i would revert to floating point ProPhoto instead and as recommended by RT whilst in RT.
Thanks for you interest.

@Keentolearn , I’m not well up on colour science but out of curiosity, what’s the benefit of using a special working profile please?

Will gladly give it a go…hope its not too complicated as I have no idea what Verbose means except when I get mad with myself and shout out loud!..I’m afraid that I am “out of my depth” on this site and don’t mind admitting that… and also its a sophisticated piece of equipment for sure(RT)

Your a very friendly community!

Hi and thanks for taking an interest.
I always wanted to learn code but never really did ( I used MicrosoftDOS in the early eighties and that put me off for life!
Can you explain what escaping looks like?

Hi Andrew and thanks for taking an interest…
Basically Joseph Holmes has created a medium sized color space ( smaller than ProPhoto and bigger than Beta RGB and Adobe 1998.This space is capable of producing more saturation than the space size itself can physically produce by the addition of and implementaion of 15 individual incremental VARIENTS (alterations) from mild saturation increases to garish saturation increases. Comes in a package…all the varients are utilised through the medium of ASSIGN PROFILE in your Application and not through Convert Profile…no harm done to your file but the color can be simply changed to your liking …just looks the way you want it without any posterisation or structural damage to your file numbers. In the package there are another 15 Varients that go about Desaturating your image incrementally to a genuine B/W
Joseph Holmes Color space goes all over the place without changing shape itself.Where all this gets to is in the printing side of the house…REDS ORANGE YELLOW are utilised right out to the printable edge …also Magentas and a very decent bit of Blue hums on paper. The sacrifice is that the greens are not indulged beyond what you can print.And you haven’t used a huge color space in the first place that now requires squashing down to run smoothly through your printer profile causing problems and faded colors.
If you work on screen exclusively then it may not be particularly beneficial .
Sorry for being so long winded.