Adding a second strand of yarn to make a cuff on a slipper

I am trying to make a slipper pattern, TV Slippes or TV Booties or Dorm Slippers. With this pattern, I can use two strands of yard to make the sole portion of the bootie. With this pattern the suggestion is to use 37 stitches with two strands of yarn. After knitting 14 rows, I drop one thread and continue to knit with the single into each loop, so in essence I am now knitting with 74 stitches on the needle, for a number of rows until I am ready to add the cuff. My pattern gives the instruction for making the cuff with a single thread, but in the past I had a pattern that made the cuff with two strands of yarn. I used two contrasting colors for the sole and cuff and a solid color for the body of the slipper.

My question is this: How do I add a second color to make the cuff and have the correct number of stitches for proper width of the cuff? :??

Do you mean you still need 74 stitches but you want to alternate colors, a two-color cuff? If this is the case, just attach the second color and ‘take turns’ with the colors on alternate stitches, stranding the color not in use across the back. If you want to just double the yarn again. . . . :??