Touching color

Why is the touching color block so laggy? I need it for my game for a school project and It makes it very choppy. I can't use touching sprite since I use the paste pen function to paste it to the background sprite to get a scrolling background. In scratch, it seems to work fine so I'm wondering why it is buggy here.

Use clones instead of stamps.

I would but I am not sure how to do that and make it scroll still. Here is my project link. (The problem is with the trees and the rocks.)

[scratchblocks]
when I start as a clone
forever
if <key [left arrow] pressed?> then
change x by (-10)
end
if <key [right arrow] pressed?> then
change x by (10)
end
if <key [up arrow] pressed?> then
change y by (10)
end
if <key [down arrow] pressed?> then
change y by (-10)
end
end
[/scratchblocks]

Ty I completely overlooked a simple solution.