If, like me, your eyes grow tired of white lettering over dark backgrounds try two remedies. Enlarge the font (a lot!) by doing Command and + (plus) several times in succession. To go back to the original size do Command and the - (minus.)
Or, have a technicolor laugh as you hold down at the same time these three keys, Control, Option, Command, then touch 8. (Not the keypad 8, I mean the 8 in the line of keys above qwerty, etc.) To toggle back to the original color scheme do these same 4 keys. Try it, you might like it.