Corporations must file tax returns in all U.S. jurisdictions imposing an income tax. Such returns are a self-assessment of tax. Corporate income tax is payable in advance installments, or estimated payments, at the federal level and for many states.
An ashen skin color is a result of inadequate oxygen circulation or perfusion.
The grey coating may be due to a fungal infection called candida (oral thrush). You need to see your doctor who will put you on a liquid antifungal medication if this is what is going on.