Oncidesa - Discolored but firm pseudobulbs - rot? viral?

[merbyderby]

I have had this Oncidesa Hwuluduen Chameleon for over a year now, and it just rebloomed. Within just the last few days, the two newest pseudobulbs have become very discolored. I immediately thought it was rot but they're totally firm, no soft spots.

I water when just dry, they have fans running in the cabinet and humidity is around 50-60%.

I'm secretly hoping that someone will say this is somehow nothing, but prepared for surgery if needed! Mostly I'm also wondering if this is rot, viral, or how I could prevent in the future.

[Roberta]

Did it perhaps get a blast of particularly bright light? Looks a bit like sunburn, and I can suspect that the newest, most tender pseudobulbs might be more sensitive than the older ones. Definitely not virus, and if they are firm, I really don't suspect an infection.
Also, you are likely keeping it a bit too dry... Oncidium-tribe orchids don't want to dry out, unlike Phalaenopsis or Cattleya that do want to approach or even reach dryness.

[estación seca]

Yes, sunburn or heat damage on Oncidium pseudobulbs looks just like this. If not light, any chance it got too close to a heater?

[merbyderby]

Ah! It DID recently get relocated directly under a lower grow light for a few hours, thanks to one of my kids "helping". I moved it back, but the timing aligns.

Thanks to both of you - I've only had my orchids get a purple-ish tinge from too much sun but haven't seen a pseudobulb get it like this. So much to learn...