I wanted to make a small picnic blanket for a mini teddy bears picnic, so decided to give the plaid stitch a whirl. I used this tutorial;
https://www.whistleandivy.com/2017/08/how-to-crochet-buff...

Loved working this pattern! Once you sort out which colours go where, it’s so easy AND there’s only the ends of the three yarn ends to sew in when you’re done.

I used;
sky blue - for the ‘dark’
lighter blue - for the ‘mid’ and
white - for the ‘light’ colour.

I made a square then worked a round of reverse single crochet to finish it off.