The default Widget Component materials are using an Unlit shading model. The Unlit shading model passes the color information into the emissive channel of the material. If you wanted your 3D widgets to not be emissive or alter the look of them in other ways, you will need to make your own material.
Note that The Widget Component expects a Material Instance with specific parameters in the material. Check out the Widget3DPassThrough Material for examples.
Here is what you’ll need to do:
- Create new Material with a TextureParameter node labeled “SlateUI” and connect it to base color
- Create Material Instance of material created in previous step
- Put Material Instance in Material slot of your Widget component.
Bonus: Look at the Widget3DPassThrough Material to see how to setup tinting and opacity