Blue first time around... then Yellow around several months later....
Like a Jedi, ones color can change sometimes as the wielders focus or ideals change with age or experience...:)
My 'Combat Style' Test used: http://www.quotev.com/quiz/725647/What-Form-of-Lightsaber-Combat-are-you-most-suited-for
Form VI: Niman
Niman, the sixth, is the most balanced, (and some say powerful) of all the styles; it has no specific strengths, but no specific weaknesses either...
You are a dangerous foe to face on the battlefield, as there is no one way to fight you; you adapt on the spot, altering your tactics to face your opponent. You have mastered many of the other styles, and put them together into a lethal combination for your duels. Notable users include General Grievous & his MagnaGuards, Obi-Wan Kenobi, Starkiller, Darth Maul, and Darth Krayt.
Learn more in general about Lightsaber Colors and Combat Styles: Crystals: http://starwars.wikia.com/wiki/Lightsaber_crystal