Distinguishing ROI within an image with a different color

I have a image named as TM10.jpg. After segmentation, the result is displayed as i2.jpg. I am trying to fuse those images together where I would like to highlight the result in the fused image with a separate color. The fused image is displayed in i1.jpg. I want to display the brightest region in the center by a green color. I came up with a solution shown in i3.jpg. Here, the background is completely black. I want the center to be green and the background color as similar as in i1.jpg Any suggestion would be very much appreciated.

I=imread('TM10.jpg');
J=imread('i2.jpg');
figure,imshow(J)
I=RemoveWhiteSpace(I);
figure,imshow(I)
J=RemoveWhiteSpace(J);
figure,imshow(J)

[rowsI colsI numberOfColorChannelsI]=size(I);
[rowsJ colsJ numberOfColorChannelsJ]=size(J);
if rowsJ ~= rowsI || colsI ~= colsJ
    J = imresize(J, [rowsI colsI]);
end
% If it's grayscale, convert to color
if numberOfColorChannelsI < 3
  I = cat(3, I, I, I);
else
  % It's really an RGB image already.
  I = I;
end
% If it's grayscale, convert to color
if numberOfColorChannelsJ < 3
  J = cat(3, J, J, J);
else
  % It's really an RGB image already.
  J = J;
end
J = uint8(J * 256);
% Specify the color we want to make this area.

redChannel = J(:, :, 1);
greenChannel = J(:, :, 2);
blueChannel = J(:, :, 3);
allBlack = zeros(size(J, 1), size(J, 2), 'uint8');
just_red = cat(3, redChannel, allBlack, allBlack);

figure,imshow(just_red)

C = imfuse(I,just_red,'falsecolor','Scaling','joint','ColorChannels',[1 2 0]);
imshow(C)

Answer 1

[Image Analyst]

Use imoverlay(). Or see these:

How to overlay a foreground image over a background image? - MATLAB Answers - MATLAB Central

Image overlay using transparency | Steve on Image Processing

[Warid Islam]

Hi @Image Analyst,

It worked. I have another issue. The result is shown in s.jpg. It can be seen that there is a blue border on the right and left side of the image. Is there any way to remove those?