0x14 ( 20 )  Global Transparency Colour
  
BitsDescription
7:0Transparency colour value (soft reset = 0xe3)

* Note: This value is 8-bit, so the transparency colour is compared against the MSB bits of the final 9-bit colour only.

* Note: This colour only applies to Layer 2, ULA and LoRes. Sprites use nextreg 0x4B and the tilemap uses nextreg 0x4C for transparency except in text mode