CTIA artifacts in blue/green, GTIA in 400/800 artifacts in green/blue and GTIA in XL/XEs artifacts in red/blue.
It's said that all PAL GTIAs are missing one red color, which is substituted by doubled brown color. Indeed, my tests show, that first color (#1) and last color (#15) are very similar or same.
Latest PAL GTIAs from China have annoying bug in 'GTIA modes', where some bits are displayed with high luminance. I have one report of such chip, it's production week is 9120 (end of May 1991).
CO14889 PAL CO14805 NTSC CO20120 SECAM
|joystick trigger inputs
|PAL clock input
|color delay line adjustment input (sometimes called DEL)
|color signal output
|luminance signal output
|composite sync output
|for synchronizing ANTIC & GTIA (when low and in HBLANK, pmg data on bus will follow)
|main oscillator input
|fast phase 0 output
|phase 2 input