Theme: Update to dark blues (#33148)
Theme: Update to dark blues (#33148)

darkBluePrimary = less purple and bit more aligned with the theme
darkBlueSecondary (text) = bit less saturated, meaning a bit brighter.
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana