Object Tracing with Particular Color
As you're probably starting to realise this is a very big field with a number of different methods which you can try.

If you want to try to use colour, you can try transforming from RGB to HSV space, which attempts to decouple the colour from the "lightness", this may improve your lighting inconsistencies.

The next problem is how to track your object. If you know the object's colour distribution (histogram) then you can use backprojection to assign a likelihood to each pixel being that colour, then perhaps you could simply track the centre of mass of the back projection.

Alternatively, you could look into template matching, where a template is scanned across the image and areas which match this template closely are scored more highly than non-matches, giving you likely areas for where the object is.

If you have any more specific information about what you are trying to acomplish, it will be easier to help you: do you have an example input image, with targeted highlighted?