[Drunken F00l]

I think you can acheive the change color effect that you want by running the following command while looking at an entity:

Code:

e_render 2 255 0 R G B

Replace R, G, and B with values from 0-255. The three values stand for red, green, and blue respectively. 0 means none of that color and 255 means all of that color. You can combine the colors to make others (e.g. full yellow has an R and G value of 255 and B value of 0).

Trail is something I could certainly add to a later version.