ChromePicker Alpha channel reverts to 1 when changing RGB inputs

How to replicate the issue:

1 - Go to https://casesandberg.github.io/react-color/
2 - On the Chrome Picker, click on the arrow to see the RGBA inputs

3 - Change the A input to 0

4- Now change the value on the R input to something else
5 - The A input it's now back to 1 - When the 0 value we put previously on the A input should have been maintained.

Start with the ChromePicker component and its RGBA input handling, then reproduce the steps in the issue by setting alpha to 0 and changing the R value. Done means the alpha input remains 0 after another RGB value changes, without regressing the other Chrome Picker inputs.

Written by the indexing model from the issue text.