UPD: 06.26.2021
I am pleased to publish a description for the mosaic crochet overlay technique. Description for crocheting in the round or from bottom to top, lots of photos, verbal description for each row and links to videos.

The Potholder #1: a total of 51g
Color A: Scheepjes SKIES 24g (40.8 m/ approx. 44¾ yds)
Color B: Scheepjes Bloom 27g (43.2 m/ approx. 47¼yds)
The Potholder #2: a total of 48g
Color A: Scheepjes Bloom 26g (41.6 m/ approx. 45½yds)
Color B: Scheepjes SKIES 22g (37.4 m/ approx. 41 yds)
The Potholder #3: a total of 46g
Color A: Scheepjes Bloom 24g (38.4 m/ approx. 47¼yds)
Color B: Scheepjes SKIES 22g (37.4 m/ approx. 41 yds)

Hook size 3.75 mm.
The size of the potholder is 19 by 19 cm (app. 7½″ by 7½″).

Technique: Double filet crochet (Interlocking filet crochet) with diagonals. Worked in the round.
Skill level: Advanced

Hook size 4 mm.
The size of the potholder is 18 by 18 cm (app. 7″ by 7″).
The pattern contains a graph and Right-Handed instructions.

I crocheted the potholders with four strands of cotton yarn 600m/100g. On potholders # 1 and # 3 I replaced one thread at a time with a thread of a different color. And I got a gradient.
For one potholder, you need a total of 55g of yarn. About 25g (37.5m / 41 yds) for crocheting without diagonals and 30g (45 m / 49 ¼ yds) for crocheting with diagonals. It is better if you have a small amount of extra yarn, since yarn consumption depends on a persons tension.

Many thanks to all testers, I managed to make the description much better. They did an amazing job testing my patterns.

I’m so excited to share this pattern with you, please do share your progress with me. Have Fun. Svetlana