Hi Nicolas, the solution to colours appearing above the Bollinger Bands was to remove colour zones that were on the chart associated with Pivot Points.
I can tell you I didn’t even know you could add colour zones to the Pivot Points! But there they were… besides I used another chart to “set as template” that didn’t have any Pivot Points colour zones on it to launch a new chart with which to build these multicolour indicators on… Just more of the same unusual things I experience everyday loggin into this platform.

Update to prior post:

The grey only appears on the 4 hour 1,000 unit £/$ chart if DEFPARAM CalculateOnLastBars = 1,500 and less, but not 1,550 bars and above.
Experimenting with lots of different chart units and CalculateOnLastBars amounts it ‘s hard to figure out the logic?

1,000 chart units and 2,000 last bars works but 500 chart units and 1,000 last bars doesn’t?

Could you please explain the relationship and why does it need 1,500 last bars if the max lookback in only 365 bars for the Vix Fix? Thanks.