During a workout I often see arches with the wrong color. For example it should be yellow (Z4), but the arch is blue (Z2). I see this very often in different workouts (I do the „Build me up“ plan at the moment) and it is very confusing.
Edit: I canˋt attach pictures? Why?
I think the forum requires a minimum number of posts before you can attach pictures, so my guess is that you have not posted enough times. I’m not sure what the threshold is, though.
Yeah it does that to me too. But when I get closer it changes back to the right color… good thing is on the side of the screen you can see your next set.
Yeah I think you have to be member trust lvl 2 to post pics.
Thanks Liz for your reply. So there is no problem with my setup.
But how can Zwift get this wrong? The efforts on the left are always correct, so you just have to copy this color and paste it on the arches. 
Zwift manages to screw up the simplest things. 
There are little twerks to Zwift that don’t work. I wouldn’t think it would matter that much becuz of the intervals on the side of the screen. Have u contacted support yet?
I’m going in zone 5 and the arch is blue.
I have a theory… the arches are the wrong color only when you enter into a set of intervals that include multiple power targets, like in Liz’s picture. She is entering into a set of 2x 30sec at zone 5 followed by 30sec recovery. Mash those two power zones together and you get the blue arch.
BroScience!
I thought so at first, Mike. But no, I’ve seen that even with a single effort.
Exactly. Thatˋs what drives me crazy. 
never doubt BROSCIENCE!!!
YES! Exactly! 
1+
Hmmm, 
I wonder… Its weird cuz it does it on the single intervals too. 
Doesn’t drive me that crazy but it drives my eyes crazy
I’ve recently encountered this problem, as shown below.
I haven’t encountered this problem like Liz Jones did above. In this case, I was doing a set of 3 over-unders that were 2 minutes @215W, 1 minute @240W (arches should be orange and red). Above, I was at 215W, heading to the segment that requires 240W.
I wonder if this has something to do with how the software handles intervals. Below is a code snippet from the .zwo file for this custom workout.
<IntervalsT Repeat="3" OnDuration="120" OffDuration="60" OnPower="0.95449996" OffPower="1.0545" pace="0" OverUnder="1"/>
This is how you define any interval. The first field is the number of repeats. Note how the first field is always “OnDuration” or “OnPower”, and the second is “OffDuration” or “OffPower”. In this case, I’m going easy then hard. It’s always in workouts like these where my arch colors are messed up. I have workouts where I have the intervals set as hard, then easy (e.g. a regular set of VO2max repeats), and the colors are normal. Perhaps Zwift is hard coded to show the “Off” interval as blue.