diff --git a/Platform/Apple/virtual/src/plasma/gameloop.pla b/Platform/Apple/virtual/src/plasma/gameloop.pla
index 88117716..8bd9d8ca 100644
--- a/Platform/Apple/virtual/src/plasma/gameloop.pla
+++ b/Platform/Apple/virtual/src/plasma/gameloop.pla
@@ -99,6 +99,42 @@ word            = $0018, $FFC5
 word            = $002D, $FFD3
 word            = $003B, $FFE8
 
+byte skyGndTbl1[] = $00 ; lo-bit black
+byte              = $00 ; lo-bit black
+byte              = $00 ; lo-bit black
+byte              = $02 ; violet
+byte              = $08 ; green
+byte              = $0A ; lo-bit white
+byte              = $0A ; lo-bit white
+byte              = $0A ; lo-bit white
+byte              = $20 ; hi-bit black
+byte              = $20 ; hi-bit black
+byte              = $20 ; hi-bit black
+byte              = $22 ; blue
+byte              = $28 ; orange
+byte              = $2A ; hi-bit white
+byte              = $2A ; hi-bit white
+byte              = $2A ; hi-bit white
+byte skyGndTbl2[] = $00 ; lo-bit black
+byte              = $02 ; violet
+byte              = $08 ; green
+byte              = $02 ; violet
+byte              = $08 ; green
+byte              = $02 ; violet
+byte              = $08 ; green
+byte              = $0A ; lo-bit white
+byte              = $20 ; hi-bit black
+byte              = $22 ; blue
+byte              = $28 ; orange
+byte              = $22 ; blue
+byte              = $28 ; orange
+byte              = $22 ; blue
+byte              = $28 ; orange
+byte              = $2A ; hi-bit white
+
+word skyNum = 0
+word groundNum = 0
+
 ;==================================================================================================
 ; Definitions used by assembly code
 asm __defs
@@ -252,6 +288,19 @@ asm isBlocked
         rts
 end
 
+asm setColor
+        txa
+        pha
+        bit setROM
+        lda evalStkL,x
+        ldy evalStkH,x
+        jsr $6009
+        bit setLcRW+lcBank2
+        pla
+        tax
+        rts
+end
+
 asm goMon
         bit setROM
         jmp $FF69
@@ -373,6 +422,18 @@ def nextMap()
   initMap()
 end
 
+def nextSky()
+  skyNum = (skyNum + 1) & $F
+  setColor(0<<8 | skyGndTbl1[skyNum])
+  setColor(1<<8 | skyGndTbl2[skyNum])
+end
+
+def nextGround()
+  groundNum = (groundNum + 1) & $F
+  setColor(2<<8 | skyGndTbl1[groundNum])
+  setColor(3<<8 | skyGndTbl2[groundNum])
+end
+
 def kbdLoop()
   word key, func
   while TRUE
@@ -418,6 +479,9 @@ initCmd('.', @strafeRight)
 
 initCmd('N', @nextMap)
 
+initCmd('Y', @nextSky)
+initCmd('G', @nextGround)
+
 initMap()
 
 ; Main keyboard loop
diff --git a/Platform/Apple/virtual/src/raycast/render.s b/Platform/Apple/virtual/src/raycast/render.s
index 06c44a62..ba8f4af3 100644
--- a/Platform/Apple/virtual/src/raycast/render.s
+++ b/Platform/Apple/virtual/src/raycast/render.s
@@ -12,6 +12,7 @@ start:
 	jmp initMap
 	jmp renderFrame
 	jmp getMapCell
+	jmp setColor
 
 ; Conditional assembly flags
 DOUBLE_BUFFER	= 1		; whether to double-buffer
@@ -61,40 +62,6 @@ mapNameLen:	!byte 0		; length of map name
 nMapSprites:	!byte 0		; number of sprite entries on map to fix up
 nextLink:	!byte 0		; next link to allocate
 
-; Sky / ground colors
-skyGndTbl1:	!byte $00	; lo-bit black
-		!byte $00	; lo-bit black
-		!byte $00	; lo-bit black
-		!byte $02	; violet
-		!byte $08	; green
-		!byte $0A	; lo-bit white
-		!byte $0A	; lo-bit white
-		!byte $0A	; lo-bit white
-		!byte $20	; hi-bit black
-		!byte $20	; hi-bit black
-		!byte $20	; hi-bit black
-		!byte $22	; blue
-		!byte $28	; orange
-		!byte $2A	; hi-bit white
-		!byte $2A	; hi-bit white
-		!byte $2A	; hi-bit white
-skyGndTbl2:	!byte $00	; lo-bit black
-		!byte $02	; violet
-		!byte $08	; green
-		!byte $02	; violet
-		!byte $08	; green
-		!byte $02	; violet
-		!byte $08	; green
-		!byte $0A	; lo-bit white
-		!byte $20	; hi-bit black
-		!byte $22	; blue
-		!byte $28	; orange
-		!byte $22	; blue
-		!byte $28	; orange
-		!byte $22	; blue
-		!byte $28	; orange
-		!byte $2A	; hi-bit white
-
 skyColorEven:   !byte $20
 skyColorOdd:    !byte $22
 gndColorEven:   !byte $20
@@ -1850,36 +1817,8 @@ copyScreen: !zone
 	rts
 
 ;-------------------------------------------------------------------------------
-setGndColor: !zone
-	jsr readKbdColor
-	bcs +
-	sta gndColorEven
-	stx gndColorOdd
-+	rts
-
-setSkyColor: !zone
-	jsr readKbdColor
-	bcs +
-	sta skyColorEven
-	stx skyColorOdd
-+	rts
-
-readKbdColor: !zone
-	jsr rdkey
-	sec
-	sbc #'0'
-	bcc .bad
-	cmp #8
-	bcs .bad
-	bit opnApple
-	bpl +
-	ora #8
-+	tay
-	ldx skyGndTbl1,y
-	lda skyGndTbl2,y
-	rts
-.bad:	jsr bell
-	sec
+setColor: !zone
+	sta skyColorEven,y
 	rts
 
 ;-------------------------------------------------------------------------------