Change Background Color Based On Cell

Ok, here is the scenario. If there is a non-vb way of doing this, I am all ears. I am not the best at VB,but I am learning.

Cell A1 through A40 I have text values of days of week, such as MON,TUE, SUN, etc. Some of these cells have a green color background (user adds the background color throughout the week.

What I am looking to do is key off of =Today() and determine if the text matches the day of the week. If it does, it changes the background color of that specific cell such as A1 to a No Fill background.

Here is what I have done so far.

I have a new column that I determine if the Text value = the day of the week, such as MON, TUE, etc. If it matches I put a 1 value in a cell. What I would like to do is to change one of the cells A1-A40 automatically to a no fill (changing the color from a green background to a blank).

I thought of conditional formatting, but here is the problem, the user through out the week will be highlighting cells A1-A40 with a green background. If you use conditional formatting, it will flip the color to a no fill if it matches, but the next day (when today is not equal to the text day) it changes it back to whatever the user used as a background color. So I would need to change it for good, until the user adds the green color back.

Example:

Todays Day = MON

TUE
WED
SUN
MON (Flip background color to a no fill)
SAT
MON ((Flip background color to a no fill)

Thank you for your help.