Rust color on Vanda leaves.
 

I am very new to orchid growing. I have two very young vandas that are developing a rust color on the leaves. Is this something to be alarmed over?

I think that is just the "suntan" that leaves show when they are near the upper limit of the light they can tolerate. As the sun shifts, make sure that it's not getting too hot from direct light that it might be suddenly getting.

Thank you for the response, Roberta. I will change their location and try that. I have them in a greenhouse with a 70% black out shade.

That sounds like low enough light... Unless that changes more, it is probably OK - go out there at midday and make sure that the light isn't sneaking around that shading some place - like from an open vent.