I'm not sure if this might be A) intentional, B) a viewer quirk or C) a Linden issue.
While trying to do something simple like:
The object seems to retain those values, as shown by the output. Editing the object and inspecting the Feature tab and Light Color shows R: 255, G:
188 B: 255. Given how the face color works, it seems like the values should be R:255, G:
127 and B:255.
Any values used for the vector, in the script, result in a slightly 'off' value in the picker, greater than the script input value 'converted' to 255 'scale'. Given the subtle nature of light and face colors, I can't actually tell if the rendered value in world is incorrect. Might this variance be intentional because it is emitted light vs a reflective face?
*Edit for version info: