Spalting Bright Yellow?

I have an elm hollow form that has developed a bright yellow color on one side while drying. I've never seen this color develop before. It's on the inside as well so assumption is that it will have to be part of the final look. Anyone seen this before? Some new kind of mold? I dry my natural edge and hollow forms in paper bags so plan to throw away the bag this one was in. Maybe I need my drying bowls to practice social distancing now.

 

I don’t have experience with yellow mold specifically, but found this reference among many others:
https://healthida.com/yellow-mold/
Following recent suggestions from others here about mold on my oak and maple, I have had great luck (so far) with wiping off mold and then spraying with a citric acid solution. After about two weeks, I remain mold free.

 

sapwood?

Is it punky?

 

Not really sapwood since it's done end grain top to bottom and the yellow covers a lot of a side and up to the opening. Not punky at all and developed while drying.

 

Is it close to a working still?, creek over limestone?, what is a sulfur source?

questions questions

 

Done and came out better than expected. I put a couple rounds of DNA and then mineral spirits on the yellowed areas. It toned it down some but not a lot. Decided to go for it and after sanding and some oil it seems to have blended in fine. The right half of the vessel is where the bright yellow was. Hope over time it doesn't come back to bright yellow.