# Color Library by Guy Walker
# www.logoarts.co.uk

To Aqua
  Output [0 128 255]     # return aqua rgb color
End

To Dark :Hue
  # output rgb list midway between :hue and black
  Repeat 3 [
    Make "Hue ButFirst LPut Int (First :Hue)/2 :Hue]
  Output :Hue
End

To Hex :Num
  # convert hexadecimal value to RGB list
  If Not (Count :Num)=1 [Print [Hex value must be single number!] StopAll]
  ForEach "Hex First :Num [
    If Not Number? :Hex [
      Make "Hex Unicode :Hex
      If (:Hex>96) [Make "Hex :Hex-87]     # A to F
      If (:Hex>64) [Make "Hex :Hex-55]     # a to f
      If Or (:Hex<10) (:Hex>15) [Print [Hex value 0-9 and a-f only!] StopAll]]
    Make "Num LPut 17*:Hex :Num]
  Output ButFirst :Num
End

To Hue :Theta
  # Output RGB hue list from angle :Theta
  Make "Red Round 127.5*(1+Sin :Theta)
  Make "Green Round 127.5*(1+Sin (:Theta+120))
  Make "Blue Round 127.5*(1+Sin (:Theta+240))
  Output (List :Red :Green :Blue)
End

To Hue2 :Theta
  # Output RGB hue list from angle :Theta
  Make "Red Abs 255*Sin :Theta
  Make "Green Abs 255*Sin (:Theta+120)
  Make "Blue Abs 255*Sin (:Theta+240)
  Output (List :Red :Green :Blue)
End

To Invert :Color
  # return invert or negative color
  LocalMake "Red 128+(127-Item 1 :Color)
  LocalMake "Green 128+(127-Item 2 :Color)
  LocalMake "Blue 128+(127-Item 3 :Color)
  Output (List :Red :Green :Blue)
End

To Leaf
  Output [0 255 128]     # return leaf rgb color
End

To Light :Hue
  # output rgb list midway between :hue and white
  Repeat 3 [
    Make "Hue ButFirst LPut Int (255+(First :Hue))/2 :Hue]
  Output :Hue
End

To Rose
  Output [255 0 128]     # return rose rgb color
End