modified colors

[asnyv]

Some playing around related to #38

Added a couple of extra color palettes together with the equinor theme (taken from the color scales available in plotly). Maybe not ideal to have multiple versions of the equinor theme, but installing multiple themes made it quick to test different ones. Final solution open for discussion, this PR is made to have a basis for further discussion.

The added themes are named equinor-alt1 (the default in webviz-config/plotly when it comes to color scales for plots) and equinor-alt2. The alt2 has a bit "stronger" colors for the discrete map.

[magnesj]

We have a category palette in ResInsight that works well in many contexts: https://github.com/OPM/ResInsight/blob/4f89e38334f6567c6a380ef6c4ed630fbd403570/ApplicationLibCode/Application/Tools/RiaColorTables.cpp#L672

[asnyv]

We have a category palette in ResInsight that works well in many contexts:

@magnesj thanks! will have a look :) based on the naming, I guess maybe contrastCategoryColors is the most suitable of those, considering we sometimes use transparency/tint to grade internally in a main color (i.e. for statistics).

[asnyv]

I went for a combination of two relatively different color sequences from the plotly.colors.qualitative library, D3 and Light24. The first 10 are with the very discrete D3, and then the next 24 from Light24 will of course have less "discreteness", but think it is still a lot better than what we had before. Many fancharts on top of each other will of course still be messy due to the opacity. Also changed the colorscales for sequential to the common viridis and for diverging to spectral Example using Drogon: First 10 ensembles (D3 only): First 20 ensembles (10 from D3 + 10 first in Ligth24)