Applying k-means on histopathological images

Hi all:

I am applying k-means clustering algorithm on histopathological medical images to classify the pixels into classes. Everything is OK when applying k-means, but I have a tiny problem: When running k-means function(which is available in matlab) many times, image pixels appear in different colors each time. Can we make the colors of pixels the same when applying the k-means function many times?

Regrads,

Safaa