You got Sans! You could say you're jokes are a bit Humerus. C'mon, throw me a bone here! No, but seriously. You're a funny person, and you're loyal to your family and friends, and when you make a promise; you'll do everything in your power to keep it.
Purple represents perseverance! The common phrase used for this in the game is "Stay on the lines". This is because, in the game, you are turned purple during the Muffet battle and have to stay on a set of three lines. Overall, you are a shy, intelligent artist who doesn't give up on anything. You probably aren't a procrastinator, either.