How do you change the PSP background color?

One of the most-asked questions here at PSPworld is how to change the background image on the PSP. Well, as of right now there is no easy way. The background image changes shades depending on the current month. For instance, March's color is light green, and in a couple days everyone's PSP will switch to pink. Until someone creates a hack or Sony enables an option in a firmware update, the only way to change your background image is to change the date in the Settings menu to a previous or future month. Images of all 12 months/colors are after the jump. Note that the PSP's screen is very hard to capture correctly with a digital camera, so colors may not be exact.