With opacity < 100%, lower resolution tiles much darker than full resolution

[mccalluc]

Looking at https://portal-prod.stage.hubmapconsortium.org/browse/dataset/d55e751748bd094ff5b0b55befb08d41, I've turned the opacity down to 0.2, and zoomed in. When I pan to the side, the lower resolution tiles are much darker than the full resolution tiles... When the full resolution does load, it brightens up. At full opacity, I don't see this.

Is this a known issue?

[ilan-gold]

This is a bug with Viv....will need to think on this one. Or rather this is a regression. Perhaps the regression just needs to be noted and the issue fixed here (which is possible). Basically we want excludeBackground as a prop to MultiscaleImageLayer if opacity !== 1 which was the default in Viv before we removed opacity as a prop from MultiscaleImageLayer (it now lives on the extension).