Update colours

[aaronw22]

• Make bluedark and bluelight more blue and less teal for better contrast
• Make orangedark less poopy coloured
• Consider changing discrete palette to use teallight instead of tealdark for added contrast, although changing the blues may achieve this

[JackBuckley]

Colour suggestions:

• Dark blue: #10485e
• Light blue: #196f91
• Sky dark: #2aaeb8