Conditional Formating when row does not equal or contain reference cell's value

All,
Wife is going thru her credit card charges in order to sort them for the accountant.
How do I create conditional formatting to allow her to see which entries she has not completed and to catch typing errors (I know she can do copy/paste, but she prefers to type).

What I'm envisioning is a way to do conditional formatting so that C2 is Yellow when data is not matched and Green, when any of the values in D2:S2 are equal to C2.

Should I just create a hidden column where I sum D2:S2 and compare it to C2 in conditional statement?
I do want to catch mistakes where she accidentally types more then one entry per row.

I've attached sample file with just few entries, vs. several hundred/thousand that she might have.
Obviously, all I did in the C2:C2 cells is Fill Color to illustrate desired result.
I listed 3 desired outcomes, but really, all that's needed is "proper entry"=Green and anything else (no fill or color) for anything else.

Thank you for your time.

Excel formatting Example.xlsx

Hi
1st. formula Green

Formula:

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2nd. formula Yellow

Formula:

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3th. formula RED

Formula:

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