function GetColorBetween(StartColor, EndColor: TColor; Pointvalue, Von, Bis:
 Extended): TColor;
var
 F: Extended;
 r1, r2, r3, g1, g2, g3, b1, b2, b3: Byte;
 function CalcColorBytes(fb1, fb2: Byte): Byte;
 begin
  result := fb1;
  if fb1 < fb2 then
  Result := FB1 + Trunc(F * (fb2 - fb1));
  if fb1 > fb2 then
  Result := FB1 - Trunc(F * (fb1 - fb2));
 end;
begin
 if Pointvalue <= Von then
 begin
  result := StartColor;
  exit;
 end;
 if Pointvalue >= Bis then
 begin
  result := EndColor;
  exit;
 end;
 F := (Pointvalue - von) / (Bis - Von);
 asm
  mov EAX, Startcolor
  cmp EAX, EndColor
  je @@exit
  mov r1, AL
  shr EAX,8
  mov g1, AL
  shr Eax,8
  mov b1, AL
  mov Eax, Endcolor
  mov r2, AL
  shr EAX,8
  mov g2, AL
  shr EAX,8
  mov b2, AL
  push ebp
  mov al, r1
  mov dl, r2
  call CalcColorBytes
  pop ecx
  push ebp
  Mov r3, al
  mov dL, g2
  mov al, g1
  call CalcColorBytes
  pop ecx
  push ebp
  mov g3, Al
  mov dL, B2
  mov Al, B1
  call CalcColorBytes
  pop ecx
  mov b3, al
  XOR EAX,EAX
  mov AL, B3
  SHL EAX,8
  mov AL, G3
  SHL EAX,8
  mov AL, R3
  @@Exit:
  mov @result, eax
 end;
end;

//------------------------------------------------------------------------------
// Function for getting mixed color from two given colors, with a relative
// distance from two colors determined by Position value inside
// MinPosition..MaxPosition range
// Author: Dmitri Papichev (c) 2001
// License type: Freeware
//------------------------------------------------------------------------------
function GetMixedColor(const StartColor,
 EndColor: TColor;
 const MinPosition,
 Position,
 MaxPosition: integer): TColor;
var
 Fraction: double;
 R, G, B,
  R0, G0, B0,
  R1, G1, B1: byte;
begin
 {process Position out of range situation}
 if (MaxPosition < MinPosition) then
 begin
  raise Exception.Create
  ('GetMixedColor: MaxPosition is less then MinPosition');
 end; {if}
 {if Position is outside MinPosition..MaxPosition range, the closest boundary
  is effectively substituted through the adjustment of Fraction}
 Fraction :=
  Min(1, Max(0, (Position - MinPosition) / (MaxPosition - MinPosition)));
 {extract the intensity values}
 R0 := GetRValue(StartColor);
 G0 := GetGValue(StartColor);
 B0 := GetBValue(StartColor);
 R1 := GetRValue(EndColor);
 G1 := GetGValue(EndColor);
 B1 := GetBValue(EndColor);
 {calculate the resulting intensity values}
 R := R0 + Round((R1 - R0) * Fraction);
 G := G0 + Round((G1 - G0) * Fraction);
 B := B0 + Round((B1 - B0) * Fraction);
 {combine intensities in a resulting color}
 Result := RGB(R, G, B);
end; {--GetMixedColor--}