Changing Colors

I have another question - sorry. I am knitting a throw made up of several squares sewn together. The pattern for each square is a heart in the centre, on a different colored background, with a different colored border. The square is knitted from the bottom upwards so there are five rows of just the border but then on the sixth row, there are six sitches in the border color, several in the background color, and then one stitch in the heart color then going back to the background color and then border. I don’t know how to change the colors without having strands everywhere. Should I be doing intarsia or the Fairisle method?
Sorry for the long description,
Thank you.

It sounds like intarsia. That’s too much stranding for Fair Isle.

If you’re doing blocks of color, then you’ll be doing intarsia, with one strand for each ‘chunk’ of color.