Strategies to convert a bitmap into OR-color sprites for MSX 2

Actually I managed to solve it by brute force (using random palette combinations instead of a lot of nested loops).

Hopefully soon I will have something cool to show.

If there are no other sprites I see no reason to why one combination would be better than another.

With other possible sprites on the line you might want to take into consideration what colors you get if one of the sprites are blanked due to having too many sprites on the line.
In that case the 8 9 and 12 combination sprite won't take any colors not originally assigned to the sprite.
A 1, 4 and 8 combination sprite could suddenly show color 1, 4 and 5 as a result.
(I think, I haven't tested any of this.)

If the sprite with color 8 have pixels set for color 9,12 and 13 too (even if it is unnecessary.) the sprite will keep its shape even if the two other sprites are blanked out.

I was referring to a situation where a number of colours can be represented by multiple combinations of OR-sprites, and whether there's a good reason to pick one combination over another. If there's no performance issue (as you suggest, Grauw), then what's left to consider is bore's sprite flickering situation.

https://youtu.be/0ZePpFKaeks?t=3369

Usas, see those cyan creatures on the floor (any idea what these creatures are called?). At some point there are five of 'em and things start flickering. If have the impression that a whole cyan creature flickers, not just half of it due one sprite, you can test by mouse-clicking youtube to pause the video. So I wonder if this is how everyone makes their game: if sprites on a row are used up, a whole NPC disappears, rather than a sprite layer.

Hence, it'd be nice to know whether it really doesn't matter what colour combination is used, or whether coders want the lowest amount or highest amount of bonus colours for their sprite characters.

If you don’t cycle the entire sprite OR-group, then depending on which subsprite is cycled you will get different colours or the entire sprite will disappear if it’s the first. I don’t think it’ll look good and cycling the entire group seems the sensible approach, I don’t recall seeing it done otherwise.

What could be interesting is to design the sprites such that if only the first sprite is shown you still get a readable silhouette, and then if there’s too many sprites on a line you render only the first sprite, instead of flickering between them. So sort of a LOD system where the sprite fidelity is lowered as needed. Though it does sound like a hassle tbh, so I would only attempt it if the game design absolutely requires it for some reason.