Si quieres un numero pequeño de colores, prueba con esto:
Código Delphi
[-]
case Random(6) of
0: shape1.brush.Color:= clMaroon;
1: shape1.brush.Color:= clGreen;
2: shape1.brush.Color:= clOlive;
3: shape1.brush.Color:= clNavy;
4: shape1.brush.Color:= clBlue;
5: shape1.brush.Color:= clTeal;
6: shape1.brush.Color:= clRed;
7: shape1.brush.Color:= clLime;
8: shape1.brush.Color:= clYellow;
end;