[OneDiscover] Histogram log.level color indication

[kertal]

📓 Summary

Important

• It's already doable in DataViewMode
• In ES|QL more it depends on [ES|QL] [Unified histogram] Add a breakdown dropdown to the ES|QL histogram #186369

When log.level is selected as a breakdown field, Discover's histogram should be displayed in a mode that is optimized for the consumption of log levels, which means it should be easy to detect log levels of critical, error, warning severity by applying term mapping to colors (tbd) and Breakdown: Filters, here's an example how it looks like in lens, and this is configureable in the Lens embeddable Discover:

Color mapping:

Breakdown:

TBD:

• which colors to use
• which terms to use for the Filter (e.g. error, err, critical, critical, warn, warning)

✔️ Acceptance criteria

• Extend UnifiedHistogram so it's Breakdown can be switched to Filters , that can be configured
• Extend UnifiedHistogram to allow colors by term mapping
• Make use of this enhancement to show the following terms with matching colors in the histogram when log.level is selected as Breakdown field:
  • critical
  • error
  • warning
  • info
  • debug
  • Other log levels
• Make use of this enhancement in the Logs Contextual Presentation

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)

[kertal]

Currently blocked by #191988

[gvnmagni]

Hi all, following a conversation with @LucaWintergerst I tried to explore a couple of options in order to have a quick fix in Amsterdam theme that would solve the problem of having the severity level Error too orange instead of closer to red tones.

I am specifically mentioning Amsterdam as a theme, because for Borealis I would love to be able to create a new Severity Color Palette that could be shared across the whole product, I am currently in the process of mapping all different cases and I will keep you updated about this separately.

For now, the important thing is to fix this issues of red-orange tints.

What I did is simply trying to re-evaluate the scale of reds that we currently use, leaving the orange/yellow tones only for Warnings

I personally suggest Option A, with warmer tones bt I would love to hear from you all what you think.

Current mapping and tokens used with proposals A and B

Proposals for updated palettes

Color codes

Current State (8.16)		|	Option A	|	Option B
Fatal 		#CC5642		|	#BD271E		|	#BD271E	
Emergency 	#CC5642		|	#C73729		|	#C1342C	
Alert 		#DA5E47		|	#D24635		|	#C5423A	
Critical 	#E7664C		|	#DC5640		|	#C94F48	
Error 		#DF9352		|	#E7664C		|	#CD5D56	
Warn 		#D6BF57		|	#D6BF57		|	#D6BF57	
Notice 		#BECFE3		|	#BECFE3		|	#BECFE3	
Info 		#90B0D1		|	#90B0D1		|	#90B0D1	
Debug 		#6092C0		|	#6092C0		|	#6092C0	
Trace 		#D3DAE6		|	#D3DAE6		|	#D3DAE6	
Other 		#D3DAE6		|	#D3DAE6		|	#D3DAE6