flipping the image across the y axis

if you said it works for one dimension, why not use the same for all 3 dimensions of RGB?

subplot(1,2,1); imshow(A); title('original')

[r c ~]= size(A)

for dim=1:3
    for i=1:r
        for j=1:c
            Aa(i,j,dim)=A(i,c-j+1,dim);
        end
    end
end

subplot(1,2,2); imshow(Aa); title('flipped across vertical axis')