As per my understanding, you are trying to have a custom color scheme for the clusters(labels) generated using K-Means. You can use the Colormap paramenter for labeloverlay function. For further details and examples, refer to the Create Custom Colormap documentation. Here’s a snippet with a simple implementation.
A = imread('coins.png');
t = im2bw(A)+1;
B = labeloverlay(A,t,'Colormap',[1 0 0; 0 0.9 0]);
imshow(B)
