The yellow is on my soft palate and sorta feels like a dome when i touch it with my tongue. could this be oral cancer?

Yellow: Unless you consume alcohol to excess, or unless you smoke tobacco or marijuana, chances of this being oral cancer is low. May be an infection, such as Thrush. Dome-like shape may be a torus. If you really want an answer to your question, call your Dentist for an examination. And you should, especially if you're dealing with an infection.

Unlikely, but: Unlikely, but warrants an exam. See oral surgeon.