Drag event doesn't work

[qinfanpeng]

Version: 2.12.1
While trying to drag Alpha slider to change Alpha, it doesn't work. and i got these message:
non-passive event listener to a scroll-blocking 'mousewheel' event. Consider marking event handler as 'passive' to make the page more responsive.

[casesandberg]

There is a related issue here: angular/components#4221. From what I understand, it is just a warning for a performance optimization and shouldn't break anything. Are you using a default color picker or importing the Alpha component itself?