196 The number which follows the ‘logical colour’ is referred to as the ‘actual colour’ and is as follows: 0 Black 1 Red 2 Green 3 Yellow 4 Blue 5 Magenta (blue/red) 6 Cyan (blue/green) 7 White 8 Flashing black/white 9 Flashing red/cyan 10 Flashing green/magenta 11 Flashing yellow/blue 12 Flashing blue/yellow 13 Flashing magenta/green 14 Flashing cyan/red 15 Flashing white/black Thus the statement VDU 19,3,6,0,0,0 will set logical colour 3 to be cyan. So if in MODE 4 , a two colour MODE , you wanted black letters on a yellow background you would issue the command:
VDU 19,1,0,0,0,0 VDU 19,0,3,0,0,0 Alternatively, you could string the whole lot together as VDU 19,1,0,0,0,0,19,0,3,0,0,0 This combination of the COLOUR statement and the VDU 19 statement enables a very wide range of effects to be obtained. There are also calls which enable the flash rates of the colours to be altered as well. See chapter 43 on *FX calls. Syntax COLOUR Associated keywords VDU , GCOL