I tried what Obsttorte suggested and came up with the following texture called plaster_01_coloured. Just copy the txt-file into the materials folder and rename it to *.mtr
You can find the new texture in DR directly under the plaster_01. Just create a brush, apply the new texture, convert it to func_static and give it the "_color" spawnarg (the underscore has to be there). Just as for the lights, there will be a button with which you can choose the colour you want. Note that the colour change is only visible ingame, not in DR.
Edit: As for changes, I really did exacly was Obsttorte wrote and exchanged "diffusemap textures/darkmod/plaster/plaster_01" with
The stuff he wrote after that meant that you can do this for each texture by replacing "diffusemap FILEPATH" with
for the texture. This adds said color button.
Edit2: For colours there are always two ways to express them: One is the range from 0 to 255 (8 bit), the alternative is in ranges from 0 to 1. You can get from the 0-1 range to the 0-255 by multiplying the number with 255. E.g. the value 0.7 represents the value 0.7*255=178.5 DR uses 0-1 in the spawnarg, the 0-255 is used in the field below.
Edited by Destined, 18 July 2017 - 09:16 AM.