Nope 4 colours.
The other came in in 1972, I think and was lilac. G-AZEB, G-AZEC and the returned LIAT G-BCCV, which also served with LIAT in lilac. Don't know what it was meant to represent though
Some strange cheat lines on leased aircraft as well; G-AYXB ('71 orange and red) and G-AXLM/N (green)