Favicon improvements

[ryankeairns]

Relates to #64695

As part of the recent branding related changes in Kibana, the favicon has been updated to the Elastic cluster logo. It looks great, however it could be even better:

1. To better differentiate from other Elastic properties (namely our website), we could utilize a variation of the logo. Specifically, we could use a monochrome version (presuming it still adheres to guidelines). With this approach we would need both a white and black version so that it remains visible in both dark and light mode, respectively.
2. Additionally, a variation of some sort that differentiates tabs running a local environment would be a nice enhancement for those working on Kibana.

[elasticmachine]

Pinging @elastic/kibana-core-ui (Team:Core UI)

[snide]

cc @JessSmithSup who might have some ideas.

[JessSmithSup]

Thanks for including me @snide
On the branding side, we are trying to eliminate the use of secondary (monochromatic) logos where we can, especially in highly visible areas. I would suggest the full-color cluster for the main Kibana dashboard. I don't know that the consistency with web and product is a bad thing.

Maybe local environments can use the monochromatic versions if we need a differentiator there.

[jpcarey]

it would be great if this was a configurable item to allow a custom icon to be added (maybe in the kibana advanced settings UI?). If you only deal with one deployment, you'd never bother to change it - but when you have ~ 5 different deployments that you are jumping between, having a different icon per deployment would really help with tab sprawl.

[xeraa]

I've written up a quick workaround with a browser plugin to go from this:

to that:

https://xeraa.net/blog/2020_custom-favicons-for-production-and-order/
It also gives you fine grained control to differentiate between different environments, projects,...

[alexfrancoeur]

This feels related to some of the discussion in #35210