[grapeshot]

If using composite video and a PAL TV, you can also blend colors by using alternating horizontal stripes because PAL TVs use a delay line to cancel the chroma information with the line above it. Exactly what color you got would depend on the specifics of your TV's decoding.

[rusk]

Yes. I believe the term was a "raster split". There was a limitation to how many colours you could use for your sprites, and using this technique you could effectively double-it. As long as your characters were on different horizontal portions of the screen. The bitmap brothers (Creatures, Mayhem in Monster Land) were notorious for this and other sweet tricks. Remember how there used to be a border? They figured out how to get sprites in there. Amazing towards the end of its life all the ways developers found to squeeze out those extra tricks from the ageing hardware.

[exlurker]

The border was "opened" for sprites by the crack group 1001 Crew in the beginning of 1986.