Update : I did it!!! I used Serial.parseint function of arduino and everything worked like magic and on vb.net side i sent strings like 255,255,255
bUT I WOULD STILL LOVE IF SOMEONE GIVES A GOOD EXPLANATION OF ENCODING AND SERIAL DATA
and one more question : I am seeing that not all rgb codes work as we see on computer screen can this be fixed I have good quality piranha led super flux 5 mm