Weird colour scalability

Hi guys,

I can’t get rid of this weird colour scalability, i don’t know why but when I render in 4k with anti aliasing I see this circular effect instead to have a nice smooth blur colour.

Any ideas?

This is called banding

Here is one solution for it: [TUTORIAL] Blue noise dithering PostProcess Material to fix banding in low-contrast gradients - Unreal Engine Forums