Blue, Silver and Pink Firmware 1.5 PSPs @ SuccessHK
Now, this is just a guess, but these three colors of PSPs probably didn't come shipping from the manufacturer with version 1.5 system software on them. Regardless, SuccessHK has blue, silver and pink japanese PSPs with firmware 1.5 for sale at price tag of $221. While that maybe a little on the expensive side, you don't have to worry about bricking your PSP downgrading it to 1.50. Keep in mind that these are Japanese PSPs and games come with region control. However, if you do with to get your hands on one of these, you can check them out using the link below.
Buy Blue, Silver, and Pink FW 1.5 PSPs here...
Via
PSPUpdates