I too wish there were some "dummies" guides. While it may sound basic to some, it will help those less adept with the ins and outs of RW and it could lead to new and different assets being released.
I will drop my 2c here - if it is anything like the standard point light, if you double click on it, it should open the right hand spec detail window and you can change the light colour there. cant guarantee that works for headlights and hope I am not sounding like I am trying to teach you how to suck eggs.
Let us know how you go - it adds to the information base
Grant
I am off next week on a 10 week, 35 hour training course on Photoshop (at $500

) so I can better understand reskining etc - hopefully that will be one less part of TS13 to give me grief...