CastOn 60 sts in German Twisted

Small center pull balls with the two longer amount of main color and yarn butterflies w the third main color and the CC diamonds. Each diamond uses approx 17’ yarn.

Yarn Butterflies
https://www.edieeckman.com/2019/11/26/how-to-wind-a-yarn-...

Intarsia: start new strand w tail at front of fabric, between needles, old color drape over the new color. Work next sts in new color and snug up strands.
Interlock strands along vertical and diagonal edge of color changes by holding old color to the left and drawing new color from underneath. This works to interlock no matter if diagonal leans left or right or if working knit or purl stitches.
Weave in tail by threading onto a fine size 18 tapestry needle. Insert through fabric to bring strand to back and maintain interlock loop when anchoring on the bac. Then duplicate stitch as suggested by Arenda Holladay or bury the end through center of a strand as suggested by Ann Berk.

Intarsia Tips:
https://thewoollybrew.co.uk/blogs/news/intarsia-a-very-be...

Duplicate stitch the diagonal lines
https://techknitting.blogspot.com/2016/04/duplicate-stitc...
https://youtu.be/EkNBjHikKLI

you would start 4 separate strands at the top for the lines. So the row starts with one st of color b then work Color mc, add one line st, then a new strand for the other line, continue with the same strand of color mc, one st of color a, a new bobbin of color mc, work with the same color mc, then add two strands for the next two lines , continue with color mc, end with one st of b. A total of 9 separate threads.
I would add that for the lines I used one long strand and folded it in half and started with the middle of it, each end going off to create a separate line. So there were 4 less ends to weave in on that end of the design.