Hey, here’s an example of how to do this.
Your material doesn’t actually make sense, you can use a vector parameter directly as a color value instead.
Here’s a color picker UMG widget, it’s just 3 regular sliders and a border widget to preview the color. By default sliders go from 0-1, so that works for Value and Saturation, but you’ll have to multiply the Hue sliders value by 360 to get the full range. Then use a HSV to RGB node to make a linear color variable, promote that to a variable, you will use this as the glow color for your material.
The last bit is just setting the color of the border to preview the color.
The widget:
Next, set up your material. Yours will be different obviously, but just as an example. Make a Vecto Parameter node and call it GlowColor. Multiply it by a scalar value to increase the strength, then multiply it by your mask to mask out non-glow areas.
Then, in your character, or wherever you want to do this, i.e. wherever you are adding your widget to the viewport, do something like this:
The “Cube” would be your mesh. It’s unnecessary to do that on tick, but as a simple example it should get you in the right direction.
