Always hide specific y-axis

[jfshiuan]

Say I have some graph on y-axis 1. This is the primary metric I am trying to show, and I do want this y-axis shown.

I also want to do some color-coding in the background. I have an index associating days with time periods, and I want to show which time period each day belongs to. Something like this:
.es(index=time_periods, split=PeriodName:50).lines(stack=false, fill=2, width=0).if(operator=ne, if=0, then=1, else=0).yaxis(yaxis=2, position=right, max=1)

It's basically an area chart that serves to color-code the time periods. The only problem is that this y-axis has no meaning, and could confuse people. I would like to hide this y-axis.

(The reason I'm using another y-axis is because I want the primary graph to dictate the min/max of the y-axis. Another solution to my problem is if I could somehow dynamically calculate the maximum value of my primary metric within a given time period...)

[tbragin]

@jfshiuan Timelion is now part of Kibana. Could you file this issue in https://github.com/elastic/kibana/issues ?