Just masking the sword and laser in Halo Reach to change their colors. If you have AE you can use the Change Color effect when indoors and not around lights of the same color.
A few times in this tutorial I sort of goofed up trying to do things that I didn't know how well they'd work. Like Thel's eyes. After it didn't work with the chroma keying method, I probably would have manually gone in and masked his eyes.