jQuery UI Slider with multiple ranges - background bug

jQuery UI Slider with multiple ranges - background bug

I'm trying to create slider with 2 ranges and add some color to background, it's OK with max value 100 (line 9): jsfiddle - ok

Problems appear after changing it, from max:100 to max:95: jsfiddle - bug

Maybe where is a better way to do this, maybe i miss something, please help me.

Thx for attention.