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function getHiContrastColorForColor  pColor
    local tR, tG, tB, YIQ, tRGBtriplet
    put RGBFromAnyColorFormat (pColor) into tRGBtriplet
    put item 1 of tRGBtriplet into tR
    put item 2 of tRGBtriplet into tG
    put item 3 of tRGBtriplet into tB
    put ((tR * 299) + (tG * 587) + (tB * 114))/1000 into YIQ
    if YIQ >= 128 then 
        return "black"
    else
        return "white"
    end if
end getHiContrastColorForColor

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function RGBFromAnyColorFormat pColor
    # take a color as color name, hex or RGB and return RGB
    local tRGBtriplet
    if "#" is in pColor then  // convert hex to RGB
        put _RGBFromHex(pColor) into tRGBtriplet
    else if  "," is not in pColor then // if not hex and not RGB convert color name to RGB
        put _RGBFromColorName(pColor) into tRGBtriplet
    else
        put pColor into tRGBtriplet
    end if
    return tRGBtriplet
end RGBFromAnyColorFormat

function _RGBFromColorName pColorName 
    # Convert any color name to RGB
    # taken from: https://lessons.livecode.com/m/2592/l/125746-translating-a-color-name-to-an-rgb-numeric-triplet
    local tRGBColor, tTool
    put the tool into tTool
    if pColorName is not a color then return "Error: not a color"
    create invisible button
    if the result is not empty then return "Error"
    set the backgroundColor of last button to pColorName
    set the foregroundColor of last button to pColorName
    set the backgroundPixel of last button to the backgroundPixel of last button
    put the backgroundColor of last button into tRGBColor
    delete last button
    send "set the tool to tTool" to me in 10 milliseconds
    return tRGBColor
end _RGBFromColorName

function _RGBFromHex pHex
    # Convert Hex to RGB
    local tRGB
    put char 2 to -1 of pHex  into tRGB
    put "," after char 2 of tRGB
    put "," before char -2 of tRGB
    repeat with x = 1 to 3
        put baseConvert(item x of tRGB, 16, 10) into item x of tRGB
    end repeat
    return tRGB
end _RGBFromHex

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function colorToRGB pColor
    local tColorRGB

    if pColor is a color then
        set the colorOverlay["color"] of the templateGraphic to pColor
        put the colorOverlay["color"] of the templateGraphic into tColorRGB
        reset the templateGraphic
        return tColorRGB  for value
				
    else return empty for value
end colorToRGB

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on mouseUp
   answer color
   put it into tBG
   set the backGroundColor of fld "List" to tBG
   set the textColor of fld "List" to getHiContrast(tBG)
   set the hiliteColor of fld "List" to getHiContrast(tBG)
end mouseUp

function getHiContrast  pColor
   put pColor into tRGB
   set the itemdelimiter to comma
   put ((item 1 of tRGB * 299) + (item 2 of tRGB * 587) + (item 3 of tRGB * 114))/1000 into tContrast
   if tContrast >= 128 then return "black" else return "white"
end getHiContrast

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-- colorname to RGB:

Faster, newer method (Jan Schenkel):

 set the colorOverlay["color"] of the templateGraphic to tColorName
 put the colorOverlay["color"] of the templateGraphic into tColorRGB1

Older method:

function translateColorName pColorName -- using templateButton
  set the backcolor of the templateButton to pColorName
  get the effective backpixel of the templateButton
  set the backcolor of the templateButton to empty
  set the backpixel of the templateButton to it
  put the backcolor of the templateButton into tRGB
  reset the templateButton
  return tRGB
end translateColorName

-- Choose text color based on lightness of background:
Works for most values, iffy when one of the triplets is near zero.
Based on first method from this comment from Ben Rubinstein: "In the standard formula for RGB -> HSL (Hue, Saturation, Lightness), Lightness is calculated as the average of the max and min of the RGB values.  In the standard formula for RGB -> HSV (Hue, Saturation, Value), Value is the max of the RGB values."

function calcLightness
  put the backcolor of this cd into tRGB
  get avg(max(tRGB),min(tRGB))
  if it > 150 then return "black"
  return "white"
end calcLightness


-- to & from HSV: [Monte Goulding]

function RGBtoHSV r, g, b
   if the paramcount is 1 then
      put item 3 of r into b
      put item 2 of r into g
      put item 1 of r into r
   end if
   local maxv, minv, diff, s, rc, gc, bc, h
   set the numberFormat to "0.###############"
   put r / 255 into r
   put g / 255 into g
   put b / 255 into b
   put max(r,g,b) into maxv
   put min(r,g,b) into minv
   put maxv - minv into diff
   if maxv <> 0 and diff <> 0 then
      put diff / maxv into s
      put (maxv - r) / diff into rc
      put (maxv - g) / diff into gc
      put (maxv - b) / diff into bc
      if r = maxv then put bc - gc into h
      else if g = maxv then put 2 + rc - bc into h
      else if b = maxv then put 4 + gc - rc into h
      multiply h by 60
      if h < 0 then
         add 360 to h
      end if
   else
      put 0 into s
      put 0 into h
   end if
   return round(h),round(s * 100),round(maxv * 100)
end RGBtoHSV

function HSVtoRGB h, s, v
     if the paramcount is 1 then
      put item 3 of h into v
      put item 2 of h into s
      put item 1 of h into h
   end if
  local rgb, i, f, p, q, t
  set the numberFormat to "0.###############"
  divide s by 100
  divide v by 100
  if s is 0 then put v,v,v into rgb
  else
    divide h by 60
    put trunc(h) into i
    put h - i into f
    put v * (1 - s) into p
    put v * (1 - s * f) into q
    put v * (1 - s * (1- f)) into t
    if i is 0 then put v,t,p into rgb
    if i is 1 then put q,v,p into rgb
    if i is 2 then put p,v,t into rgb
    if i is 3 then put p,q,v into rgb
    if i is 4 then put t,p,v into rgb
    if i is 5 then put v,p,q into rgb
  end if
  return round(item 1 of rgb * 255), round(item 2 of rgb * 255), round(item 3 of rgb * 255)
end HSVtoRGB