I'm looking for a clean way of making sprites that look like the following glowing circle, except in any arbitrary colour.
Originally we thought we could start with a gray-scale version of the above image (shown below) and then use the
tint parameter in
spriteBatch.Draw to change the colour of the glow.
The problem is that because
spriteBatch.Draw uses multiplicative blending to blend the tint and the colour the white parts don't stay white, they become the colour of the tint. The next image shows (approximately) what this looks like.
The other solution we thought of is to have two separate sprites, a white interior and a grayscale glow, and then we apply the tint to the glow and draw that on top of the white interior. This produces the desired effect (to a degree) but is annoying on our part since it requires is to double all the sprites we want to draw this way.
Is there any other cleaner solution that produces the desired effect for an arbitrary colour?