Had a play with colors -I found that reducing the drive in the MODE REGISTER, BIT M5, from 6dB to 0dB improved the colours, so M5 needs to be a 0, this will depend on how good the monitor is..



If you mofify the fillscreen to the following you should get lines of ifferent colors.
Code:
FILLSCREEN: 
    'character=$0B       'SPACE
     TEMP1=0   ' LINECOUNTER
     TEMP =0    'CHARCOUNTER
loop2a:
    
	WDATA = 0  ' LINECOUNTER*256 + CHARCOUNTER   ADDRESS
    GOSUB Send
                                             

LOOP3a:    '                :CHARACTERS 100011       
	WDATA = %0001011100100011  '     X CHARACTER
'   WDATA = %0001011101110111
'    if temp1 =0 then WDATA = %0001011101110111
    if temp1 =1 then WDATA = %0001000001100011
    if temp1 =2 then WDATA = %0001000101100011
    if temp1 =3 then WDATA = %0001001001100011
    if temp1 =4 then WDATA = %0001001101100011
    if temp1 =5 then WDATA = %0001010001100011
    if temp1 =6 then WDATA = %0001010101100011
    if temp1 =7 then WDATA = %0001011001100011
    if temp1 >=8 then WDATA = %0001011101100011
    
    GOSUB Send
	TEMP = TEMP + 1
	IF TEMP >= 28 THEN
    TEMP = 0
    TEMP1=TEMP1 + 1
	ENDIF
	IF TEMP1 >= 11 THEN SCREENBLANKA
 	
    GOTO LOOP3A
    
SCREENBLANKA:
	RETURN