Apologies. Perhaps I was not clear enough;
All icons are editable/customisable, EXCEPT for those of the emulators.
Those icons appear to be contained & retrieved from within the OPKs.
If I attempt, for example, to create a Game Boy theme/skin,
then I can make all assets green EXCEPT for those icons (emulators) contained within the respective OPK.
How can I work around this?