My white betta fish has developed red spots on his fins. What does this mean? Is he sick?

When I bought him over a year ago, he was completely white with some black around his eyes and face. This is what he looked like. a href="http://i181.photobucket.com/albums/x242/x2xx0/betta%20buddiesss/IMGP2745.jpg?t=1261086312" rel="nofollow"http://i181.photobucket.com/albums/x242/…/a Now he's more of a yellowish color. Over time he's developed these little red spots on his fins, and the black spots on his face have multiplied, so most of his head is black spotted. He eats fine, his temperament hasn't changed, still reacts the same way when I walk into the room and he swims around like a healthy little fella. He also flares normally when I put my finger on the gl of his tank, his gills are fine, he still poops and stuff (I don't know what else to check!) I removed all of his plants and his pebbles and cleaned his tank out thoroughly, in case he had cut himself on a plant or in case there was bacteria collecting in the pebbles. I clean his tank once every 4 days and replace the old water with distilled water. I don't know if it's normal or if he's sick. If he's sick, what should I do?