Making a blue glowing substance is easy, as long as you already know the secret to making green luminescent phosphorescent glow powder. By watching the green glow-in-the-dark procedure, you know that you will need strontium nitrate, aluminum nitrate, europium and dysprosium nitrates, and nitric acid. That will make a green glow, but if you want to make a blue version, it's a relatively easy fix...
Watch this science video tutorial from Nurd Rage on how to make blue phosphorescent glow-in-the-dark powder with Dr. Lithium.
To switch from green to blue, you simple need to swap the strontium nitrate with 590mg of calcium nitrate tetrahydrate. This simple replacement will turn your green glow into a blue neon glow.
Brought to you by one of WonderHowTo's favorite scientists, NurdRage.