Phalaenopsis Orchid Yellowing Leaves
 

I received a beautiful "Sunset Orchid" as a gift in February and for the most part haven't paid much attention past watering it once or twice a week until we recently began experiencing warmer weather here in Northern California (60 degree F at night and anywhere between 70-80 degrees F during the day). Unfortunately my condo faces West, so the best place I have for my orchid to live is my windowsill that faces SW--I thought perhaps since I live in closer dwellings, my sheer curtains and the alley would help shade some of that sun away. However, is my orchid still receiving too much sun? Should I remove it from the sill? I do keep the window slightly ajar for the most part although I forgot to leave it open this weekend. I've been watering it once a week or so, but when I returned after being gone on the weekend, I noticed a drastic yellowing of all of the leaves. Also, I noticed when the weather got warmer, my blossoms turned lighter, although last week they blossomed more buds that were the same color as I had received them back in February.

Any suggestions to how I can save my orchid?? I have not repotted it since I received it. Do I need to repot? I'm not sure what I should trim if something needs to be trimmed... Sorry if there are any repeat questions, however I glanced over the sticky's and didn't quite find my answer. If my question is answered elsewhere, I'd be happy with a redirected link as well! Thanks! :)

Pictures are attached.

I think your plant is a little sunburned - if you can, move it back from the window a bit. The roots look mostly OK. You probably don't need to repot, but you can if you want.
The sunburn markings on the leaves probably won't go away, but eventually, your phalaenopsis will send out a new leaf, and that (assuming you correct the light problem) will be unblemished. In a few years (yeah, years...) those damaged leaves will be old news.
Hope this helps!

You may like to figure out how much light is actually on that windowsill; try this method. This link will give you an idea of the light levels various orchids like.

You might find this link has useful hints for phalaenopsis care - let me know if you find it helpful. :)

@Discus, Thank you so much! Those links were very helpful! I appreciate your input:)

Great :) hope your phalaenopsis goes from strength to strength :)

Agreed it looks like it has sunburn. Personally I would repot because I don't like moss... but the roots look like they are doing fine and are growing for you so it might be fine to leave it if you can balance your watering correctly for the moss.

I wouldn't say "a little" but A LOT of sunburn.
See how the leaves have yellowish cast over fairly large area? and there are two distict "bunred" areas?

You might want to move the plant away from the location it is currently at.
Or put another layer of sheer curtain.
Or place the plant a little further away from the window if possible.