how to mask region under the boundaries accurately ?

I have an RGB image in which I have segmented certain portions of the image using bwboundaries commands in matlab. Now i want the region under the boundary to be masked with green color. For this i want develop algorithm dynamically

 & not by using imfreehand command. could any one help on this? . I have attached the rgb image with boundaries marked...

[Star Strider]

Duplicate to: http://www.mathworks.com/matlabcentral/answers/151258-how-to-mask-a-region-under-the-boundary.

Follow up with your previous question rather than posting a new one.