let red = 51
let green = 255
let blue = 51
let alpha = 128

var htmlColor = String(format:
    "#%02X%02X%02X", red, green, blue)
//htmlColor is #33FF33
print("style=\"color: \(htmlColor);\"")

//with transparency
htmlColor = String(format:
    "#%02X%02X%02X%02X",
red, green, blue, alpha)
//htmlColor is #33FF3380
print("htmlColor is \(htmlColor)")