There is nothing like a "little" heat to bring out the color in ceramics. Glazes are amazing. I always marvel how a ceramic piece is transformed once it's been glazed and fired.
To be completely honest, "little" isn't really little - these were fired to 2232* F.
Clay is messy. There is no way around it. I have an old comfortable pair of Keen sandals that I wear in my studio while I work. Over the years, they've acquired their own unique natural patina of clay and glaze splatter. A sure sign of the onset of fall and cooler weather around here is my transition from sandals to socks with sandals. The look is a definite "Glamour Don't"!