Selected Answer
What I would do is to assign each color a number value and then insert a new column next to the text and input an IF statement that outputs the correct number for each color.
Then, copy the IF statement down, apply conditional formatting to the column that now has numbers, select that column, make the text the same color as the background, resize the column to fit the icon set or symbols that you chose.
The IF statement could be something like this:
=IF(A1="Green",1,IF(A1="Yellow",2, etc...