HatchBackground

procedure HatchBackground(img: TImage32; color1, color2: TColor32; hatchSize: Integer);

Hatching may be semi-opaque.

uses Img32, Img32.Extra, Img32.Fmt.PNG;
...
img := TImage32.Create;
img.LoadFromFile('star.png');
HatchBackground(img, clWhite32, clSilver32, 10);
img.SaveToFile('star_hatched.png');
img.Free;
      
Before:
After: