If you save only one UHD Cache file and re-use it for all frames, you should not animate your objects or lights (including light color), because the UHD Cache file will be still "frozen" and will not reflect those changes.
If you calculate UHD Cache from scratch for all frames, it will work fine even with animated lights.
Also, this is a perfect case for using LightMix. Set up LightMix, render your animation with no animated light color, then compose LightMix in post production software (e.g. After Effects), and animate the color/intensity of your light there. That would work fine even with just a single UHD Cache file re-used for all frames.