There are 2 problems with Colored Decor which makes it impossible to not only change their LIGHT colour dynamically, but also impossible for them to have ANY light anytime <!-- s:( --><img src="{SMILIES_PATH}/orc10.gif" alt=":(" title="Sad" /><!-- s:( -->.
First of all, the light which is set for them (in vfxdefs.txt) is Static, which means that we cannot change light colour , at least in current Vavoom version) because static lights are stored as a separate objects (and maybe due to some more reasons).
Secondly, I found out that static light is not created at all for the things with TID > 0 (don't know why), and they should have TID so that they could be translated by script.
So, if we want to have light on them, either we should them have dynamic light (which will slow the game, plus only limited number of dynamic lights are shown at once), or we should solve those problems somehow... or we should design the maps with fixed colour set (blue/red) .........
PS. I made a colored decoration without static light, but with dynamic one and it woirked, and changed colour properly.