You might be interesting in seeing this:
Den. Enobi Purple 'Splash' by
hawaiiansunshine, on Flickr
My first impression was that there were two different plants potted in the same pot. However, after close inspection, it was found that the two different colored flowers were on the same plant--two inflorescences are splashed and one is all lavender. Researchers at the University of Hawaii indicated that this is not uncommon for mericlones. This can occur and it sure did on this plant. Orchid Center had 1000 plants of this clone. Only 5% of the plants had splashed petal flowers. The remaining 95% had all lavender flowers. The plant shown in this photo is the only one that had two different colored flowers on one plant.
By the way, my Enobi Purple is blooming bigger and better than ever. It won the Best Dendrobium in the Show at the Honolulu Orchid Society Show last month. I'll post a picture of the plant later.
As I mentioned before, buy only the blooming plants if you want to be assured of getting splash petal flowers. Otherwise the chances are good you will end up with a plant blooming only lavender flowers.