Methods for converting RGB <-> HSV <-> Hex <-> decimal in Scala / Java

ColorConversions.scala

// converts Int -> 6-digit hex String
def dec2hex(dec: Int): String = String.format("%6s", dec.toHexString.toUpperCase).replace(' ','0')
 
// converts any hex String to Int
def hex2dec(hex: String): Int = Integer.parseInt(hex, 16)
 
// convert Hue, Saturation, Value -> Red, Green, Blue
// ([Any]%360, [0,1], [0,1]) -> ([0,255], [0,255], [0,255])
def hsv2rgb(hsv: List[Double]): List[Double] = {
    val colorCode = Color.HSBtoRGB(hsv(0).toFloat, hsv(1).toFloat, hsv(2).toFloat)
 
    var rgbaBuffer: ListBuffer[Double] = List.fill(3)(0.0).to[ListBuffer]
 
    rgbaBuffer(0) =  ((colorCode & 0x00ff0000) >> 16).toDouble // r
    rgbaBuffer(1) =  ((colorCode & 0x0000ff00) >>  8).toDouble // g
    rgbaBuffer(2) =  ((colorCode & 0x000000ff)      ).toDouble // b
//  rgbaBuffer(3) = (((colorCode & 0xff000000) >> 24) & 0x000000ff).toDouble/255.0 // alpha
 
    rgbaBuffer.toList
}
 
// convert Red, Green, Blue -> Hue, Saturation, Value
// ([0,255], [0,255], [0,255]) -> ([0,1], [0,1], [0,1])
def rgb2hsv(rgb: List[Double]): List[Double] = {
    Color.RGBtoHSB(rgb(0).toInt, rgb(1).toInt, rgb(2).toInt, null).to[List].map(_.toDouble)
}

// converts hex String to Hue, Saturation, Value ([Any]%360, [0,1], [0,1])
def hex2hsv(hex: String) =
  rgb2hsv(List(hex2dec(hex.substring(0,2)).toDouble,
               hex2dec(hex.substring(2,4)).toDouble,
               hex2dec(hex.substring(4,6)).toDouble))

// converts Hue, Saturation, Value ([Any]%360, [0,1], [0,1]) to hex String
def hsv2hex(hsv: List[Double]): String = {
  val rgb = hsv2rgb(hsv)

  val rhex = String.format("%2s", rgb(0).toInt.toHexString.toUpperCase).replace(' ','0')
  val ghex = String.format("%2s", rgb(1).toInt.toHexString.toUpperCase).replace(' ','0')
  val bhex = String.format("%2s", rgb(2).toInt.toHexString.toUpperCase).replace(' ','0')

  rhex + ghex + bhex

}

def rgb2hex(rgb: List[Double]) = hsv2hex(rgb2hsv(rgb))

def hex2rgb(hex: String) = hsv2rgb(hex2hsv(hex))

def rgb2dec(rgb: List[Double]) = hex2dec(rgb2hex(rgb))

def hsv2dec(hsv: List[Double]) = hex2dec(hsv2hex(hsv))

def dec2rgb(dec: Int) = hex2rgb(dec2hex(dec))

def dec2hsv(dec: Int) = hex2hsv(dec2hex(dec))