Hi everyone. I had this question when I was using Blender, and now I have it when I'm animating in After Effects.
For example: I have a logo and I want to animate it. Let say it will be rotating in 3D space lighted by the spotlight. First it will be in the shadows, then it will come to the light, whatever. I can do that with no problem. But this is logo, it has specific RGB color and at the end of animation it should be that specific color. Insted of that logo is a little brighter or darker because of spotlight. Is there is an option where I can set color of my logo in used light or I just need to manualy set spotlight strenght, angle or something to obtain that RGB color.
Set your logo to the desired color value. Add an ambient light with a brightness of 100% and check the color values with the Info panel.
If all is good then turn off the ambient light and add your spotlight. Position it where you want it to generate the shadows you want and check the color values at the end of the move. If they are way off you may have to adjust the material options or position of the light. Find the material options by selecting the layer and pressing the A key twice.
You may also want to have a bit of ambient light to fill the shadows. If you cannot get a perfect color rendition then you could always do a cross fade between the spot light (or point light or any other kind of light) and the ambient light.
Be aware though that if you are dealing with 3D elements and you want to simulate dimensionality the lighting on the object cannot be 100% even or you will loose the 3D effect. I don 3D logos for clients all the time and I am only concerned that the average color on the least reflective part of the logo matches the company colors.