0x40 ( 64 )  Palette Index
  
BitsDescription
7:0Select the palette index to change the associated colour. (soft reset = 0) PAPERs to indices 16-23 and Bright PAPERs to indices 24-31. a subset of indices 128-255. The number of active indices depends on the number of attribute bits assigned to INK and PAPER out of the attribute byte.
Notes:
  For the ULA only, INKs are mapped to indices 0-7, Bright INKS to indices 8-15,
  In ULANext mode, INKs come from a subset of indices 0-127 and PAPERs come from
  In ULA+ mode, the top 64 entries hold the ula+ palette.
  The ULA always takes border colour from paper for standard ULA and ULAnext.