I formatted my SD card to fat32 using GParted and copied all the files from the official NOOBS Lite download: https://www.raspberrypi.org/downloads/noobs/. I unzipped using unzip command on the terminal. When I turn on the rainbow appears and the Pi gets stuck there. Red LED is on, green turned off after a few seconds. Don't know if I did something wrong or my card is broken. Appreciate your help.

  • rainbow usually means under voltage – tlfong01 Aug 23 '19 at 0:51
  • Rainbow with a good power supply on a RPi4 is 100% bound to be an SDCard that doesn't have the RPi4 kernel and firmware. – Dougie Aug 23 '19 at 9:00

Feel so dumb. Tried connecting to the other HDMI port and the image appeared, it was actually booting but showing the rainbow through that port. How do I switch from HDMI port 1 to 2 to show as default? I have to force it a little to use HDMI port 1 as it is right next to the power cable. Also, now I'm getting another error when I try to flash Raspbian full:

Error creating file system
Mkfs.fat: warning lowercase labels might not work properly with DOS or Windows
Mkfs.fat: too few blocks for viable system
Mkfs.fat: 3.0.26 (2014-03-07)
  • You answered the question but asked a new question. How to answer to an answer? You should make a new question. – Ingo Aug 23 '19 at 17:01
  • Yep, was doing the same thing. Connect your micro hdmi to the hdmi port nearest the USB C power connection. – Chris S Jan 4 at 13:13

The Boot Problems Sticky contains detailed troubleshooting steps.

Using NOOBS just makes fault finding harder.

The rainbow screen is due to missing (or obsolete) firmware.

I suggest you use Etcher to install Raspbian to a SD Card (like the vast bulk of us).

If you REALLY want to install NOOBS, make sure you have the LATEST version and follow the Foundation instructions =>

Visit the SD Association’s website and download SD Formatter for Windows or Mac.


I ran into the same problem while working on my project. It seems like a low voltage problem so make sure the power supply has minimum of 2A Output and that should fix the rainbow screen problem.

  • 2
    The rainbow screen is unrelated to low voltage it indicates missing or obsolete boot files. – Milliways Aug 23 '19 at 3:28
  • This does not really answer the question. If you have a different question, you can ask it by clicking Ask Question. You can also add a bounty to draw more attention to this question once you have enough reputation. - From Review – Milliways Aug 23 '19 at 7:10
  • 1
    @Milliways "Immediately after displaying the splash screen, the PI starts consuming a little more current. If the PI resets at that moment, it is an indication that the power supply isn't able to deliver the full current your PI requires..." elinux.org/R-Pi_Troubleshooting#Coloured_splash_screen Of course this does not mean stuck on the rainbow screen. – goldilocks Aug 23 '19 at 12:43

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