My pattern states, “change yarn to ecru” and then instructs to “yo” as the very first stitch on that row of knitting. How do you yarn over if you’ve got no established stitches in the new color?
Probably the best thing is to tie a loose knot to join the two yarn ends. (It’s awkward enough to yarn over at the beginning of a row without having to change yarns.) Later you can undo the know the weave in the ends. The yarn over will be stabilized be the succeeding rows by then.