You don't need any kind of software. Accordingly to the PC case manual, to change the color of your LED lights you have to use the remote control like that you have for your TV but a lot smaller with fewer buttons (supposedly you been provided with your computer).
With this you can change RGB lights color (usually there are other functions like, control the brightness, increase decrease led flashing mode speed etc). Hope this helps you some more.
[EDIT] All the above are valid only in the case that the shop you bought the computer have done the right installation. Again it doesn't seem your motherboard to have a RGB connector, if it was then an appropriate software would be already installed to control the RGB lights.
Use the remote...