Conditional Formatting will meet your needs:

You will need to put your "blackout" dates on the same sheet (far to the right is fine)(cond. format will not reference another sheet or workbook)

Select the desired cell (I used H11) and click Format>Conditional Formatting...

in the pop-up window, choose "Cell is" in the Condition 1 drop down and choose "equal to" in the next box, finally, enter this formula in the next box

=VLOOKUP(H11,$K$3:$K$29,1)
(adjust the $K$3:$K$29 range reference to match where you placed your date list)

Then click the Format button and choose your font color, maybe make it BOLD, too.

Click OK twice to exit back to your sheet.

copy this format to desired cells (copy>paste special>Formats)

Done

HTH