How to turn gray layers into RGB layers?

I have a normal image that I split into its RGB layers, where I make some magic with them. In order to show how the magic influences the normal image, I concatenate the RGB layers. Unfortunately, I only receive a gray image instead of a coloured image. I was told to write mat2gray*255 and then uint8. Whitout this I only received a nonsense all-white image with strange axes.

   Img_R = uint8(255 * mat2gray(abs(Img_x2(:,:,1))));
   Img_G = uint8(255 * mat2gray(abs(Img_x2(:,:,2))));
   Img_B = uint8(255 * mat2gray(abs(Img_x2(:,:,3))));

   pertImgRGB = cat(3,Img_R,Img_G,Img_B);

So, what commands do I have to add to the lines in order to get coloured single layers, and so get a coloured concatenated new image pertImgRGB? Thanks

Answer 1

[Image Analyst]

That looks right (it's not a display problem), so in that case you need to go back to the original Img_x2 and figure out why all color channels are the same.