Return CGColorRef from 'popUpViewColor' in 'ASValuePopUpView' rather than UIColor
Return CGColorRef from 'popUpViewColor' in 'ASValuePopUpView' rather than UIColor

Still return a UIColor from ‘ASValueTrackingSlider’.
The rational will become clearer in a bit - will need the ability to
override alpha value from ‘ASValuePopUpView’ and set it to 1.0.

alskipp/ASValueTrackingSlider,vantientu1703/ASValueTrackingSlider,jianyelijun/ASValueTrackingSlider,vince4/ASValueTrackingSlider,hejunbinlan/ASValueTrackingSlider,ezescaruli/ASValueTrackingSlider,elegion/ios-pods-ASValueTrackingSlider,shenyuan000/ASValueTrackingSlider,3squared/ASValueTrackingSlider,puvanarajan/ASValueTrackingSlider