A full-colour icon pack renders white with purple blotches on any screen
that declares an SGB palette zone, and only in ADVANCED. Colour there is
applied after the frame is drawn: a shader reads each pixel's red channel
and swaps in one of four palette colours. That suits the game's own art,
which is already four greys. Full-colour art is not. A yellow body is
nearly all high red, so it clears 0.83 and comes back as colour 0, white in
every palette, while the darker pixels land in colour 2, which MEWMON
paints {115,33,165}.
Art that should be left alone says so with a trueColor flag and is re-blit
unshaded. Battle pics, trainer portraits and overworld sprites all carry
one. Menu icons had no way to. The icons record has no such field, and
Sprites.iconPath returned a path alone where Sprites.path and
Sprites.playerPic both return path, trueColor. Nowhere to put the flag and
nothing to read it, so the art always met the shader.
R.sprites is the precedent for allowing it. Overworld walkers are OBJ art
drawn through an OBJ palette, the same hardware class as a menu icon, and
they carry the flag already.
iconPath now takes the record's flag through opts and returns it, and a
pokemon.icon hook may set ctx.trueColor for art it substitutes, which is
the contract pokemon.sprite already has.
PartyMenu.drawIcon skips the OBP bake for flagged art and reports its
covering rect. The bake matters as much as the shader does: obpIcon is
itself a four-shade remap on the red channel, so it flattens full-colour
art before the zone pass ever runs. The flag overrides `name` rather than
being read beside it, because a hook can substitute full-colour art for a
species that resolved to a built-in class through icons.byDex, leaving name
set. The entry-shape split from #274 does not catch that case.
The reported rect is 16x16 for the two OAM-block branches and the file's
own size for single-frame art, matching what each branch actually draws.
No vanilla icon record sets the flag, so both rect buckets stay empty on a
vanilla boot and the zone lists stay exactly the ones the states returned.
Code-Grub