Hi SP2340,
The Vanda looks like it is dehydrated...the wrinkling that can be seen in the leaves is a good indicator of this. Also, when the leaves start to turn yellow and fall off, it is either due to dehydration or cold...in this case, I'd say it is not enough water. Vandas can tolerate temps down to 50 degrees F…and even a little lower for vey short periods without suffering damage.
I would make sure that the plant is watered every day...I see a couple of root buds forming, so this plant still has a great chance of turning around. When you water, water good until the water is running off the roots....wait about 10 minutes and then water it again. I can't see the other roots on the plant...hopefully there are plenty...If they are still white after the second watering, you may need to repeat the water cycle a third time to make sure that moisture is getting through the velum coating around the roots (the white stuff).
As for the dendrobium...the plant looks very healthy, and I believe the stripes are normal. I'm looking forward to seeing the blooms when they open up.