[Monitoring] Ensure we're prepared for dark mode

[chrisronline]

Dark mode PR: #28445

We need to ensure the Monitoring app is ready for the K7 upgrade in conjunction with dark mode.

I think most of it is ready with one known outstanding issue: #28610.

Part of this work should also include upgrading to the new SuperDatePicker and that will hopefully help with removing much of our angular code.

[elasticmachine]

Pinging @elastic/stack-monitoring

[chrisronline]

It's likely this will not make 7.0, but come in 7.x

[elasticmachine]

Pinging @elastic/kibana-design

[ryankeairns]

@chrisronline I think you're safe to close this issue. While your custom header/breadcrumbs would benefit in other ways from being rewritten, they aren't having a negative impact on dark mode here. I'd suggest you close this one and continue to pursue #28610 , separately.

That said, one thing we look out for in SASS files that an cause issues with light/dark mode is hex values. I only see one and it doesn't appear to me that it is actually being applied anywhere at the code:

kibana/x-pack/plugins/monitoring/public/components/elasticsearch/shard_allocation/_shard_allocation.scss

Lines 64 to 68 in 96338a7

	&.unassigned {
	.title {
	color: #999;
	display: none;
	}

[chrisronline]

Sounds good! Closing this