conditional formatting blanks and 0 values

I made a conditional formatting by color to a matrix but when it comes to blanks and 0 values it doesn't give me the right color 
i used the following measure in my formatting and i doubled it to make the format work

>>Total Ach% 1col = SWITCH(

     TRUE(),

    [Total Ach%]>=[%timegone],

    "#32CD32",

    [Total Ach%]<[%timegone],

    "#ff0000")
thos are examples to the issue