Colour pattern of animation output looks like contour

Support Animation and Rigging
1

I have tried rendering an animation using the following video settings:

FFmpeg video
RGB
Matroska container
H.264 video codec
Loseless
Good encoding speed

The colour looks fine on the screen. But after the animation output file was converted to MP4 format, the colour became contours as shown in the picture below, just like the VGA output.

What combination of video settings should be used to make the colour look continuous?

Image3

2

If you are not aware of the file size use lossles PNG codec or FFmpeg #1 or try adding subtle noise to hide banding.