Creating a color image

I am trying to create a 256X256 image that starts out blue on the left hand side and scales down by one index every column so that it is black on the right side, kinda like in this picture but opposite direction but I cannot get this code to preform. How can I achieve this? Is there also a way to do this vertically as well, ie, blue on top scaling down to black on the bottom?

image(:,:,1)= zeros(256,256,1);
image(:,:,2)= zeros(256,256);
for i=1:256
    image(i,:,3)= [255:-1:0];
end
image=image/255;
imagesc(image)

Answer 1

[Walter Roberson]

Blue_image = zeros(256, 256, 3, 'uint8');
Blue_image(:, :, 3) = repmat(255:-1:0, 256, 1);

Please avoid using image as a variable name, as it is the name of an important MATLAB routine to display images.

[PenguinForce]

Thank you! I did not know that about the image variable name but thank you for letting me know! I appreciate your time