Brian Chan is an amazing designer (Attack of the Kraken is one of his) and this flower is an ingenious, if intense, use fo a coloured square of paper.
I only had some glossy red (a cheapo pack of coloured origami paper that loses colour all over your fingers) but persevered with it, despite the mess and the tiny size.
I still have to master the flower shaping, it sort of looks correct (and I have no doubt if i wet-folded or used methyl cellulose I could mould it more naturally , but I am happy I have got the hang of the fold.
Interestingly, the box-pleating technique to raise the leaf is similar to the “dollar flower” I have been folding from the cut-offs from A3 squares, so found that part of the model really easy. The technique of raising the colour-changed petals for the rosebud is ingenius.