Minor anomaly in measured batch size status dot

Not sure what they are but the little dots to the right of the values in the displayed fields.  I set measured volume, gravity and batch size to zero.  As expected the gravity changed color (not sure what it is but probably red) and the mouse over says the gravity is too low and gives the range. 

The Measured Batch Size stays blue and the mouseover says "Ok".  I would expect  a batch size of 0 to be not oK.