I am attempting to use a DSE24 in the composite mode, and the output picture has a green tint. Why?

This issue is the hue inversion that occurs when the mode is changed to composite – the composite hue default is not the same as the rest of the video modes. All you have to do is change the hue to the default setting (It’s 128 for composite and 0 for every other video mode) and it’ll look fine.