What Rainbow Boot Screen and Raspberry Pi Rainbow Box Mean
If you’ve been playing around with your Raspberry Pi for a while, you’ve probably already come across a rainbow pop-up screen. There’s a good chance you’ve also seen a more curious version of this, the same rainbow pattern zoomed out and blinking in the corner of the screen. This is what they mean.
The rainbow screen appears on every boot as a GPU test, but if you don’t look at the screen all the time, you probably missed it because it blinks quite quickly. However, if your screen is stuck on that rainbow screen, you probably have one of two problems.
This could mean that the kernel.img file kernel.img not loading, which means there is something wrong with the image on your SD card. To fix this, you can try a new image or try fiddling with the config page . It could also mean that your PSU is not powerful enough, in which case you might just want to try a more powerful PSU.
Speaking of power problems, if you see a rainbow cube in the corner of your screen, it means you have the wrong power source . If it’s a rainbow, it means your PSU is undervoltage. If it is red, it means overheating. Your Raspberry Pi may continue to handle any of these problems, but you should get the correct power source as soon as possible.