getColor

local function getColor(number,x_middle,x_max)
  local color
  if number<=x_middle then
    local value = math.floor(0xFF*(number/x_middle))
    color = 0xFF0000 + value*0x101
  else
    local value = math.floor(0xFF*(1-(number-x_middle)/(x_max-x_middle)))
    color = 0x00FF00 + value*0x10001
  end
  return color+0xFF000000
end