It's been about 2 weeks since my WL started to show color and sad to say it hasn't progressed much... a few other leaves starting to get a bit of white. The first leaf still hasn't even developed the ful white strip down the middle, let alone lateral coloration.
Summer here has been cooler than usual, but not to the extreme. Ie: 80 degrees average high instead of say 85.
This is my first season w WL, so I'm hopeful next year the more mature plant/bulb will get established sooner outdoors and thus color sooner. I think I'll try growing under lights in the winter to see if I can keep the color.