I just realized that when playing Raiden III NesicaX on a horizontal monitor setup (480p Nanao MS-2932) some colours are slightly off, e.g. the water at the beginning of Stage 1 is deep blue instead of the kind of yellow-greenish I have when played vertically. The same with the water background in Stage 2 or the clouds when reaching the boss at Stage 2. Everything is straight blue instead of the usually yellow-green-brown-whatever tinted colour-patterns. Just if some different colour space applies when the game is not played full-screen. I can try to capture it on a picture later, but maybe someone has an idea about that. Don't think this behaviour is intended, since the YT-Videos I can find have the authentic colours.
Update: Just verified the same behaviour with a second TTX2.
Update2: Tried to take some photos - excuse the quality, but it should suffice to see the colour difference
Tate:


Yoko:
