Blending colors in HSL

[WojTec]

Delphi-Quellcode:

function BlendColorsHueCW(const AColor1, AColor2: TColor; const AValue: Byte {0..100}): TColor;
var
  RGB: array [0..2] of Byte;
  HSL1, HSL2: array [0..2] of Integer;
  H, S, L: Integer;
begin
  GetRGB(AColor1, RGB[0], RGB[1], RGB[2]);
  RGBToHSL(RGB[0], RGB[1], RGB[2], HSL1[0], HSL1[1], HSL1[2]);

  GetRGB(AColor2, RGB[0], RGB[1], RGB[2]);
  RGBToHSL(RGB[0], RGB[1], RGB[2], HSL2[0], HSL2[1], HSL2[2]);

  H := Round((MaxHue / 100) * AValue) * (HSL2[0] - HSL1[0]) shr 8 + HSL1[0];
  S := Round((MaxSat / 100) * AValue) * (HSL2[1] - HSL1[1]) shr 8 + HSL1[1];
  L := Round((MaxLum / 100) * AValue) * (HSL2[2] - HSL1[2]) shr 8 + HSL1[2];

  HSLToRGB(H, S, L, RGB[0], RGB[1], RGB[2]);
  Result := SetRGB(RGB[0], RGB[1], RGB[2]);
end;

When ~100% then invalid result. Why?