CIE-Lab changes on Light intensity changes
I hope I get it right. You want to reduce effect of the light sources and perform the image segmentation. So basically you want to perform color based image segmentation. 
If you do want to do that on a variety of data the first step should be performing the white-balancing technique on your images, and adjust the color temperature on the same values. This ensures the same type of your illumination source, even if the sources change over time (e.g. color temperature of daylight changes). The type of the light source definitely affects your color values. Unfortunately this can be performed only on RAW image datatypes, but if you expect change of light sources and you are keen on accurate results, I would strongly recommend the white-balance process.   

For image color segmentation I do recommend mentioned CIELAB color space, because of it's independence. It does not depend on the input devices as well. The big advantage here is the possibility of separation the Lightness channel and perform segmentation only on the color ones (a*, b*). That is why this color space is more useful than for example RGB, which includes information of lightness in it's R, G, B components and the results are significantly biased due to that. However the L channel of the CIELAB corresponds more to the psychometric lightness rather than the real luminance.  The problem might be the intensity of light source, EV as well. If you get saturated and also really dark parts of the image you will not be able to restore the right color values. Other settings of the camera might have impact on the colour values as well. So if you want seriously accurate measurements and results from image color segmentation it might be really tricky. On the other hand, with a "normal" conditions and removing L channel in CIELAB color space, you can reduce the effects of the light sources on colour values as much as possible and there are not many other ways to do that. So ideally take your images with the same settings, white-balance them, transform them to CIELAB, remove the L channel and than perform color based segmentation.