MATLAB: How to add a ‘colorbar’ and set ‘clim’ to a colour image overlaid on a grey level image

climcolorbarcolormap

Hi all,
I am trying to overlay a colour image on a grey level image. However, when I try to plot the 'colorbar' and set the 'clim'. Matlab always produce a colorbar according to the underneath grey level image.
However, I want to get the colorbar for the overlaid colour image. Any suggestions would be appreciate. Thanks a lot.
%%Example codes:
greyImage = imread('AT3_1m4_08.tif');
colorImage = imread('hestain.png');
figure,
greyImagePlot = image(greyImage); colormap(gray); hold on;
overlayImage = imagesc(colorImage, ...
'CDataMapping', 'scaled', 'HitTest', 'off');
alF = 0.5.*ones(size(colorImage, 1), size(colorImage, 2));
set(overlayImage, 'AlphaData', alF);
colorbar; % This will show a grey scale colorbar not the colour one I want
set('CLim', [0 100]); % Also, the colormap limit here is not working
axis off
axis image