Do I need to use a color checker chart to detect specific colors in an image if all images are under the same constant lighting? If so, what is the best way of color correction?

I am doing a project that involves taking an image of a skin lesion and extracting six specific colors (red, white, black, light brown, dark brown, and blue-gray). All of these images are taken under the same lighting in a controlled setting. I am wondering if I need to use a color checker chart to correct the colors or if I can design thresholds for these specific colors that would be constant for all images taken under this constant lighting. If so, what would be the best way of going about performing the color correction with the color checker chart? Ideally my project is fully automated in MATLAB and any manual procedures are not favorable.

Thanks!