Is there any such thing as a non-cryogenic, liquid, "green" hypergolic bipropellant, where green means environment friendly and non-toxic?
It depends what you mean by green. All rockets end up producing vast quantities of greenhouse gases of a variety of types and degrees of harmfulness to the environment (even water vapor is a greenhouse gas). But apart from greenhouse gas emissions many fuels are also dangerous chemicals in their own right that leave toxic residues or pose leak risks or have non green manufacturing processes.
Some rocket propellants produce relatively benign water vapor and carbon dioxide such as RP1, ethanol and methane when combined with liquid oxygen or hydrogen peroxide. But these don’t tend to be hypergolic. However some work has been carried out in an attempt to rectify this situation.
It is possible to make kerosene and high test peroxide into a hypergolic combination if the kerosene is treated with small quantities of a solid energetic activator dispersed throughout with a gelling agent.
This area is currently being actively investigated by several different teams around the world: