Thank you @shanibeer! Ah, sorry, which part were you referring to, as the back of the object? The unused yarn is carried along as we crochet, I hope the photos below show:

I kept it consistent by making sure the crocheting yarn is always on the outer side (even as we change the colours), sort of "enveloping" the carry-on yarns, this kinda hides the carry-on yarns pretty neatly.
And because this pouch is crocheted in a loop, there is no need to sew in ends from the colour changes because we just bring them along and interchange the colours.
Does this help explain? Let me know :)