It seemed down to conditions as the buds developed. I bought it with 5 spikes, 2 close to blooming and 3 further off. The last 2 to open came out almost all white with only a tiny bit of purple in the center, while the original 2 had been mostly purple....
I have one that just bloomed this year and the flower is a lot more white than last year with all the red missing on the lower lip but after a few days of being open a slight tinge and a gentle flush of pink is developing which is not how it happened last year!
I just had another one open that is somewhat different looking from last year! Many of mine had only bloomed once prior to this spring so this is interesting! Some of it I would put down to being better or different on second and subsequent blooms because the plant is bigger and stronger. I'm not sure they are better, just different and I like them all!