Does feeling sourness at the back of the tongue, and the presence of a yellow color with saliva when spitting, along with intentionally swallowing the saliva while it is present, break a fasting person's fast?

The taste a fasting person experiences after cleaning their teeth does not break their fast, unless it is vomit. It is considered akin to food residue that mixes with saliva, which is difficult to avoid or distinguish. If food remains between the teeth of a fasting person and their saliva carries it, and they are unable to distinguish it, their fast is not broken by swallowing their saliva mixed with it due to their excuse. If they were burdened with not swallowing it, it would be difficult for them.