To add on to your solution, if you’re dealing with a darker scene and don’t want to mess with exposure/eye adaption or mess with your lighting AND if you still want a slightly emissive transluscent widget this method worked very well for me. Add another multiply after the last multiply that plugs into emissive color, then plug the last multiply and a vector 4 parameter into the new multiply node. Then plug that into emissive color. This creates a “Emissive boost” Parameter for the UI material. If set to black, the widget will have no emissive glow. If white, it will be fully emissive. I set mine to a dark grey and it worked very well for my scene lighting
This way you can keep the Translucent Material setting, but change the shading model to Default lit (to get both emissive and base color)
Before (fully emissive):
No Emissive:
After (slight emissive):
