So after I made my full sized practice diamond, I found that my blue criss-cross stitches were not quite meeting in the exact middle as they should. So I did a color chart of the full pattern, which is actually gold and blue diamonds with black criss-cross. While tedious to do,this was VERY helpful!! It let me re-check my diamond design and get everything to work out
Perfectly! I am so glad I took the time to do this or it would have been all off kilter by the time I got to the 3rd set of diamonds at the chest.

I've attached a drawing of the whole vest and my color chart. Hope that helps someone else design an argyle item of their own.