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.
Other less common conditions that can cause dark brown to black spots include: 1  Riehl melanosis: brown pigment condition on the neck and face. 2  Poikiloderma of Civattea: dry and scaly patches on the neck and face. 3  Erythromelanosisfollicularis. 4  Lineafusca: long skin markings.