You are doing it right. The extras will be unsewn to make the diamond shape, or you can add extra at the tip. Only at the longest (top of diamond) point, will you have every color
Cover up the top dark with your hand and you will see the effect start. The strip after you will remove both the first dark and floral. It gets a little confusing because you are working from a different angle.
Also, when you go to sew, pin them well. Some evil imp inside of me always wants to line the seams up, and they must be offset in order to line up. That is the one pattern I will baste. I guess that explains why they ended up in the ufo pile :D
To see, just line them up, then put a sheet of paper over the ones you will be unsewing. The diamond will show right up.