@Lordwarblade and @Chamëleon TBN - actually the solution is to have the colour map as you like it but it must be there to define only those areas that will change the colour when you yourself manage the colour in the Manage Hotels option in the asset info view.
As default there is no or black colour that is applied to the white mask on the colour mask - if you change it, so the asset will change - if there is no colour map defined than obviously colour change will be applied to the whole model.
So either whole black mask in the colour map, or with white parts that you want to be your hotel's brand colour later in the game.

Thanks a lot for your tests and report!

yes I've done completely unmodded, as below :)
I even rushed to check it just in case before i posted the reply :)
there is no difference whether with mods or not - I did my own asset, I checked DLC in game assets... in modded and unmodded game.

Unmodded?

@Chamëleon TBN - And yes, it seems those DLC in-game assets have only those colourable parts black - I compared that with promotional/dev diaries photos and that is weird that they had no problems. Maybe one of the updates has changed something.
If you have that DLC, can you check those hotels - i listed some of them in the bug report.

@ Chamëleon TBN - I have checked both custom assets and CO's assets from Hotels DLC - wherever they used colour variations map to allow for the colour to change - those areas remain black no matter what, with or without mods (i just checked that too). So the colours are not assigned at all, those areas remain black as in the in the image in this
bug report [forum.paradoxplaza.com] (where i had not used any colour map, therefore the game assumed i wanted full asset to have its colours changed - so yes i know that the game creates full white mask here).

@macluk

If you don't have a color mask, then the game does indeed treat the asset like it has a full white color mask. And since hotels from the DLC use the color mask to assign the color selected for the hotel chain, you'd see that applied to the entire hotel.

But if a Vanilla Hotel is black in the unmodded game and you have not chosen black as hotel color (or the entire hotel is black, not just the recolorable parts), then that would be an issue.

Can you verify this is the case?

First thing that comes to mind is if the hotel turns black when you zoom out and the LOD is activated. Then you would have a custom asset with a faulty LOD mesh or texture.

That is also probably why some of their hotels look completely black 😁

I've reported it just yesterday - in the meantime do _c (colour) map all black; if you leave it off, the asset editor will automatically create a white one as if it wanted to have colour variation there.

A bug in the Hotels DLC. So that's what happened to my Tudor hotels. Is there any chance they'll ever fix that, do you think? Have they abandoned it yet?