Slider is falling off 
Can reproduce this issue here: https://casesandberg.github.io/react-color/
Enter #00000 in HEX and using UP Arrow navigate to H and enter 500 and hit Tab.
The slider (white dot) falls off the Color section.  

<img width="1276" alt="slider_fall_off" src="https://user-images.githubusercontent.com/12789813/49835120-dca21700-fd63-11e8-8cc9-afcc9e226d22.png">
