How did sonic get his speed and color

In the video games and cartoons, he was simply born with both, but in the British comics he was granted both in a scientific experiment involving a chaos emerald. This same experiment is what created sonics enemy, Dr. Ivo "Eggman" Robotnik.

From a design standpoint, Sonic was made blue to match the American flag(when combine with his trademark red and white sneakers) and was made fast to better sell segas system, which could supposedly process information faster than other systems at the time.