Как такой вариант? Uses GraphABC;
Begin
SetWindowTitle('Разноцветная картинка');
SetWindowSize(600, 400);
For i := 0 To WindowWidth Do
Begin
r := Round(255 * i / WindowWidth);
g := Round(128 * (WindowWidth - i) / WindowWidth);
b := 0;
SetColorRGB(r, g, b);
Line(i, 0, i, WindowHeight);
End;
For i := 1 To 10 Do
Begin
x := Random(WindowWidth);
y := Random(WindowHeight);
radius := Random(50) + 20;
r := Random(256);
g := Random(256);
b := Random(256);
SetColorRGB(r, g, b);
Circle(x, y, radius);
End;
For i := 1 To 5 Do
Begin
x := Random(WindowWidth);
y := Random(WindowHeight);
side := Random(80) + 20;
r := Random(256);
g := Random(256);
b := Random(256);
SetColorRGB(r, g, b);
Rectangle(x, y, x + side, y + side);
End;
ReadKey;
End.