color fade

  ldy #0
@Loop:
  jsr WaitVblank
  lda #$3f
  sta PPUADDR ; $2006
  lda #$00
  sta PPUADDR
  lda FadeColors,y
  sta PPUDATA ; $2007
  lda #0
  sta PPUSCROLL ; $2005
  sta PPUSCROLL

  ; delay between colors
  ldx #4
: jsr WaitVblank
  dex
  bne :-

  ; next color
  iny
  cpy #8
  bne @Loop
  rts

FadeColors:
  .byt $10, $00, $0f, $0f, $00, $10, $30