add a glow filter similar to the one in photoshop.

Give it a blend mode similar to the other blend mode dropdowns

Add opacity slider

Add a hue threshold slider with a hue gradient in the slider let me pick the range of the color with 2 slider dials. This lets me pick the colors that casts a glow.

When the dials are at the opposite ends of the slider, it will select all colors. If I adjust the sliders to a narrow range, it will only select colors from between the dials.

Add a luminosity threshold slider with black to white gradient in the slider and let me pick the range of the luminosity with 2 slider dials. This lets me pick the threshold of luminosity that casts a glow.

When the dials are at the opposite ends of the slider, it will select all pixels in that luminosity range. If I adjust the sliders to a narrow range, it will only select pixels of that luminosity value from between the dials.

let me pick the glow color that is cast with an easy to use color picker.

let me pick the angle and distance of the glow.

Angle will be done via a circle angle picker like the screenshot I pasted here.

Distance will be a slider between 0px to 350px.