To build it, you'll need an RGB LED (or three separates), some resistors and an Arduino + Ethernet Shield.
The sketch uses the MQTT protocol to connect to a public broker at test.mosquitto.org. You can then control the lamp on the web, or from (practically) any language using an MQTT client.
The web page to control the lamp is uploaded (over MQTT) by the sketch itself. So, if you know a bit of HTML and Javascript, you can customise it any way you want.
Sir I want to know something. I read your tutorial. If I can't find the Arduino Uno - R3, is there any substitute device I can use except Arduino Uno - R3 or how can I make a similar device to Arduino Uno - R3 using cheap parts in electronic parts shop?
I used the Arduino Uno as I needed a device with over 16KB for my sketch. You could construct your own Arduino-a-like using an ATMega328, or a completely different microcontroller - if you're willing to change the code accordingly.