I found on Pinterest that the best way to create glowing objects, is with contrasting colors. So, I will show you my little glowing balls with and without the contrast in them...........

Without Contrast: The colors look dull and lifeless without the contrasting colors in between the bottom layer and the top. But that is okay, if your trying to draw a flashback scene or something like that.

With Contrast: you can see how the extra layer of contrast helps make the ball look more... Glowy... 😊🙃😝

Do you see what I mean?