Improve use of palette macro and use PAL_* constants (#1087)

* Improve use of palette macro and use PAL_* constants

* Use proper constant for battle stats (#1088)

* Add suggestions about function names and variables

* Add colors macro

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Co-authored-by: vulcandth <vulcandth@gmail.com>

macros/gfx.asm

@@ -22,6 +22,7 @@ DEF palblue  EQUS "(1 << 10) *"
 DEF palettes EQUS "* PALETTE_SIZE"
 DEF palette  EQUS "+ PALETTE_SIZE *"
 DEF color    EQUS "+ PAL_COLOR_SIZE *"
+DEF colors   EQUS "* PAL_COLOR_SIZE"
 
 DEF tiles EQUS "* LEN_2BPP_TILE"
 DEF tile  EQUS "+ LEN_2BPP_TILE *"