Design targets for color values or other integrated spectral values may not always be well-defined numbers. You can also search for designs where color values stay within tolerated boundaries, but it does not matter where exactly.
Such design situations can be handled in CODE using so-called ‘penalty shape functions’. However, the use of this concept turned out to be rather complicated.
We have now (starting with version 5.02) introduced a very easy definition of tolerated intervals for integral quantities: Instead of typing in the target value you can define an interval by entering 2 numbers with 3 dots in between, like ’23 … 56′ or ‘-10 … -8’. If the integral value lies within the interval its contribution to the total fit deviation is zero. Outside the interval the squared difference between actual value and closest interval boundary is taken, multiplied by the weight of the quantity.