Future date in cell to change color on that date

[Guest]

Use Conditional Formatting for the expiration date cell.
Use following in Conditional Formatting dialog:

Cell Value is
less than or equal to
=TODAY()

don't forget the = sign in the last part

Choose format Font to color red.

You can copy the Conditional Formatting set in one cell to
other cells with the format paint tool.

Hope this works for you.