I was not able to replicate this bug. Here's the steps I followed.
1- I set the 3rd color (left to right) as the base color.
2- I set the 4th color (left to right) to brightness of 10 using HSB value.
3- I began sliding the 3rd color slider further to the left (thereby reducing the brightness of all colors in the theme).
The 4th color value was reduced to zero. I did not see it pop back up. Can you help me see if I've missundrstood something in your post?
I can replicated it over and over on my end. It should be noted that I am using the web application on Chrome. Win 7 x64.
- Restart the application froms scratch.
- Don't bother changing any of the hues.
- Select the value slider for any of the secondary hues (1st, 2nd, 4th, or 5th colors left to right) and scale it down For the best effect, make sure it's below 50%. **note, seems to effect 2nd and 4th sliders only**
- scale down the value slider of the primary hue (3rd left to right) to 0% (black)
You will see the the secondary hues reduce to 0%, and loop back through 100%.
I was able to replicate this. We're looking into the cause.
Thanks for posting!