matlab - How do I change my image background to red -

I have an image with a brown ROI and black background, which I got from the IFFRED function. I want to convert that black background into red color for the following image.

There are two ways to do this

< Li> Then set in "Nain": Set (GCA, 'Color', 'R')
1. Use "Find" to get the index of black pixels and set the colors in the respective planes [1,0,0] for the red, blue and green JPG respectively.

I'm sure there are others, but these are the first two come to mind.