Quick Art Tip: Using Glow Effects When the Light Source is Darker than the Object it Glows On

I recently saw a picture in which the artist was trying to use glow effects, but ran into a problem because the shining soul that was casting the light was darker than the shirt it was casting that light on.

I gave them a couple tips, and decided to share those tips here, too.

1. When a dark-colored light source is casting light on a non-black object, especially one with a lighter shade than the light source, make the color of the glow slightly lighter than the color of its source.
 
​When the light source's color is darker than the object on which it's casting light (like the soul compared to the shirt), it makes it look like the soul is casting pure color or even darkness on the object it's glowing on.

2. Add a lighter shade of the base color to the center of the soul, so it looks more like a light source.

Here's a quick demo of what the abovementioned glow effects look like in total darkness and on clothing the color of the shirt they drew, so you can see the difference.
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The two souls on the top are both casting light the same shade as their base color, albeit not at full opacity. Notice how the shirt seems darkened.
 
The souls on the bottom are glowing their base color in the dark, but on the shirt, the glow is lighter than the base color, so they aren't darkening the shirt. 
 
I hope that quick art tip helps!