How do I change the theme of my ps3's Initial theme? The color when u turn it on?

When I turn on my ps3 it pops up PS3 with red but how can I change it to a different color?How do I change the theme of my ps3's Initial theme? The color when u turn it on?
It randomly changes. I used to use that theme but I downloaded a new one online. I now use a Bioshock theme.