This is an overlay mosaic pattern worked in US terminology.
The pattern, Cross My Heart, was released on September 1st, 2023
This pattern contains 1 large, detailed panel in the round that can be repeated to the desired size.
You will need to know the basics of mosaic crochet but there are tons of videos for beginners on YouTube.
Mosaic crochet is a dense crochet, no “holes” so is ideal for blankets, rugs, runners, cushions, etc.
You can use a variegated/print/cake yarn and allow the yarn to change colour on its own or you can use two separate colours to create a contrast in the pattern.