As your question is not clear, it is recommended to ensure what type of output you want to get.
If you want to convert segmented image into color image, it is preferable to convert binary to label using function bwlabel(). And if you want to keep the color in ROI in output image as it was in input, then its method would be different.
I rejoin the idea of Neha, first you convert your binary image to image of label using bwlabel function, second you convert the obtained image of label rmap to rgb image using :