Color changing decal with fade effect?

That would take a long time to upload but simply set the decal id to the id of the image. Upload an image by creating a decal, and inserting it by id with the insertservice, then copy the image id and use that in your script as one frame. It would take a couple minutes just to upload so good luck and If you didn't understand that tell me what you didn't understand.

Answer edit: You need a lot of images and use just plain wait() You might actually be able to set the decal's saturation to 0 (black/white) one image, then set its transparency to 0.01 and create a surface gui with a frame in it of size {1, 0}, {1, 0} to fill up the brick, and set the frame's transparency to 0.5 also, then set the frame's color to Color3.new(r/255, b/255, g/255). You might need to find a way to add up 1/255 at a time and use rainbow colors, but I have never had a rainbow colors problem. Try BrickColor.new(brickcolorname).Color and use those, but have it add up from it's last values to that color. It's hard to explain but it might work.

If you want your decal to fade look no further! Use for loops!!!

while true do
for i = 0, 1, .1 do
script.Parent.Decal.Transparency = i
wait()
end
wait(.3)
for i = 1, 0, -.1 do
script.Parent.Decal.Transparency = i
wait()
end
end

SOLVED!

while wait(0.1) do script.Parent.ImageColor3 = Color3.new(math.random(0, 255)/255, math.random(0, 255)/255, math.random(0, 255)/255) end

This script should go inside of the ImageLabel.