I have this image in Gimp:
Each red square has the same width, height, color and layer.
I want to make all red squares half blue like this:
To do this I'd make the first square half blue then copy and paste the new square to all the other red squares in the image.
Although what if there's 30 squares, copying and pasting over each square would take ages.
Does Gimp have a way that I can just change the first square and it copies the same change to all the other squares in the image?