I remember this one, from using a typewriter back about 45 years ago, when I was a kid. You could get a dual-color ink ribbon, and could shift the ribbon up to

I remember this one, from using a typewriter back about 45 years ago, when I was a kid. You could get a dual-color ink ribbon, and could shift the ribbon up to print in red instead of black. Haven't thought of or seen that for many decades.