Two different colored flower spikes on same Phal?

[twinkie]

Hello everyone,
I don't know what's happening with one of my Phals and am suspicious it could be a fertilizing problem.
One spike has blooms with lovely white and purple streaks that are ordered and overall the blooms are well shaped. The other spike has deep purple flowers with only a rim of white around petal edges, the blooms are much smaller and appear more cup shaped but do not appear misshapen.
The color and size difference is so striking am worried I've got a virus or possibly hit it with bloom fert at the wrong time? The larger white and purple stalk bloomed first, the deep purple second.
Otherwise, the plant is healthy, no root rot etc. Does anyone know what could have caused this or is this possibly normal to have two different colors on two separate stalks? Am trying to upload pics but they seem to disappear after loading.
thank you for any help!