In theory, colored flames could be added to SDLPoP.
Each room tile, including the floor with torch, is stored as two bytes, a group and a variant (modifier).
Currently, the only variant used in the torch group is 0x00.
This leaves plenty of variants for the colors.
The most basic solution would be to assign a single value to each color, e.g. 0x00 is (already) orange, 0x01 red, 0x02 green, etc.
Better would be to allow more granularity by using RGB values.
'Full' RGB would require 3 bytes, with 1 byte (0-255; 8 bits) for each primary color.
However, the colors could be stored in the available 1 byte, using 6-bit RGB.
As a plus, that would also leave two bits for possible future use.
PoP torch flames consist of two color zones (yellow core and orange lumination).
When a custom (non-0x00) value is used, the core should probably just be white.
Alternatively, the more basic solution mentioned earlier - basically 3-bit RGB - could be used, to allow modders to pick colors for both the core and the lumination.
The latter is probably a bad idea, given how limited the 3-bit palette is.
I've created a feature request ticket/issue for this on SDLPoP's GitHub.
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