Clearly show that an input is required

What
Clearly show that an input is required.

Why
Currently a required input is marked with a small red *.
It is not clear to everyone that this means the input is required.
There are many good examples of indicating this, including if the input is valid.

Possibilities could be

  • Clear text “Required”
  • Red / green input field or input box when valid / invalid.
  • Green checkmark when valid
  • etc