GauRailControl2 v0.3

rednet.open("right")

local Archi,BW,Gau = colors.purple, colors.orange, colors.yellow

while true do
  event, ID,message, distance = os.pullEvent("rednet_message")
  if ( string.sub(message,1,4) == "rail" ) then
     local value = tonumber(string.sub(message,5))
     local newColor = 0
     if ( bit.band(value, 1) ~= 0 ) then newColor = colors.combine(newColor,Archi) end
     if ( bit.band(value, 2) ~= 0 ) then newColor = colors.combine(newColor,BW) end
     if ( bit.band(value, 4) ~= 0 ) then newColor = colors.combine(newColor,Gau) end
     rs.setBundledOutput("back",newColor)
  end
  if ( message == "ping" ) then
    os.sleep(1)
    local myColors = rs.getBundledOutput("back")
    local value = 0
    if colors.test(myColors,Archi) then value = value + 1 end
    if colors.test(myColors,BW) then value = value + 2 end
    if colors.test(myColors,Gau) then value = value + 4 end
    rednet.send(ID,"rail" .. value)
  end

end