How to Enable Background Blur and Custom Screen Colors

Modern UI lets you replace the flat dirt or dark background behind menus with a solid color and a Gaussian blur of the world behind it, which makes GUI screens look far cleaner.

Turning On the Blur

Open the Modern UI settings screen and find the background or appearance section. Enable the blur option there. The blur samples whatever is rendered behind the current screen, so it is most noticeable when you open your inventory or a menu while the world is visible. If the effect looks too strong or too weak, adjust the blur strength setting next to the toggle. Some setups disable blur automatically when a shader pack is active, so if nothing changes, check whether a shader is running.

Setting a Background Color

In the same section, enable the custom background color option and pick a color with the color picker. This color is drawn behind menus instead of the vanilla background. You can combine it with the blur so the color tints the blurred image, or use the color alone for a flat, minimal look.

Notes

Both options apply to the mod's own screens and to vanilla-style screens the mod reworks. If a particular screen still shows the old background, that screen is likely not yet handled by the mod.