I am working on a christmas tree skirt and I am kind of stuck on Row 37 of the pattern.
I know there are a few different videos on here showing different methods of adding the second yarn color… I am just not sure which on to use since I am only using the 2nd color for 20 sts.
Please Help 
For this you’ll want to do intarsia. You’ll knit with the red to where the green starts, then knit with a small ball of green. Use another strand of red to work to the next box and yet another for the green.
In essence, each section will have it’s own small ball of yarn, so you’ll have a lot of strands hanging off the back until the boxes are done. When you switch from one color to the other, make sure that you hold the yarn that you’re stopping over to the left and bring the new color up from under it. This will help them to twist and prevent holes.