Omitting nulls/blanks in a Conditional Formatting Measure

 I have solved it. It's very emberrassing. The problem was I was refferring to a different column in the measure than I wanted to apply the conditional formatting to. Bothe measures in the question will work just fine as long as we change the column name. The correct Measure looks like this:

DateStatus = 
VAR TodayDate = TODAY()
VAR ApptDate = MAX('factPropertiesRemAppts'[RemJobdtmAppt])
RETURN
    SWITCH(
        TRUE(),
        ISBLANK(ApptDate), BLANK(),  -- Leave blank if there is no date
        ApptDate > TodayDate, "Green",
        ApptDate = TodayDate, "Yellow",
        ApptDate < TodayDate, "Red"
    )