#49, #35 - red and blue are too bold. Try adding more gradient in just the red, from dark red to light red (almost white), then light blue to dark blue.
#20, #36, #50, #51 - what would it look like on a black background? Need to make a version that visible on a black background. My sheet metal workers will be wearing black T shirts with the logo on the left chest (and possibly a large logo on the back).