Cattleya walkeriana 2 out of 3 buds turned yellow
 

I have had Cattleya walkeriana v. semi-alba x sib (Baby's Tears x Elixir of love) about 6 months and it produced a flower spike from the base of a pseudobulb with 3 buds. The first 2 had turned yellow and stopped growing while I was away for 5 days. The terminal bud is alive and swelling. It looks a bit like a flamingo's beak. There was the usual sweet sap on the buds. the plant is healthy, producing new roots. Its in chunky bark in terracotta with extra holes drilled on the side of the pot. I generally run water with dilute fertilizer over the roots every 2 or 3 days so I left a little water in the tray for humidity while I was gone. I have read all the walkeriana posts because I have another walkeriana x intermedia 'Midnight blue' for over a year. It's growing well, producing pseudobulbs and roots but no buds. I give it complete darkness at night.
If anyone has experience to share, please do.

Photos help! There could be a number of issues at play, but I suspect the plant didn't have enough reserves to create enough flowers. Did you repot it when you bought the plant?

Bud is starting to open on C. walkeriana x semi alba
 

It has a very rich deep red/purple lip. The other petals are white, the pink tinge is from the led light. I had been growing it outside but brought it into the house because of extreme weather that was possible while I was away. Maybe it was the change of location. I am just grateful to get one bud to open. I hope it develops fragrance. Your posts and videos online have been very helpful.

Ah yes, moving it while in bud could cause blast, unfortunately! Is this the clone 'Carmela?'

I don't know if it is from Carmela. This is what the tag is Cattleya walkeriana v. semi-alba x sib (Baby's Tears x Elixir of love). It has now opened fully and has a glorious fragrance like honeycomb with a hint of lemon and the purple on the white petals is not from the led but the true pigment.

Ah, I see! Totally different plant, then! Enjoy!