Poor export quality

I work on a small project and use a generator for the intro. The playback in FCPX is distorted, but appears OK when paused. The problem is the picture is also distorted on the exported file. I don´t understand why?? The project properties is 1920x1080 50p.

Attachments show paused picture in FCPX and playback of the Master File.

Only one image here.

are your settings set to better performance or better quality?

Here is the second attachment. This is the paused picture in the viewer.

Import "Create optimized media"
Export settings: Better performance/better quality or master file - the quality appears more or less the same.

Attachment too large... Here it is..

I´m sorry. Artifacts appeared during uploading... Two smaller pictures is attached.

Not clear ewhat you mean by distorted. If you're referring to the quantization banding in the first image that's an artifact of 8-bit compression. There isn't enough color depth in the format to create a smooth gradient. Depending on how you need to output you could try high quality output maybe ProRes 4444 or XQ. Another thing you can try is to add a little noise to the image to break up the very smooth gradient. That can make compression easier.