Increase contrast in post header

[humphd]

Caused by:

This needs to get fixed so it's more accessible.

[agarcia-caicedo]

I played around with some colours, and I think its better to just use two colours for the post header. Otherwise the only colours we could use would be a blue, white, and black.

This one keeps the dark to #2944, but changes the blue to #5995C9

This one keeps the light colour to #A4D4FF, but changes the blue to #2A5A83

This one keeps the blue at #3670A5, but changes the light to #AFFDFC

The blue doesn't work well with any dark colour, so I can't present a variation

[cindyorangis]

Gives me dark mode vibes #77 ;)

[humphd]

@strawberries73 is going to give this a try.

[strawberries73]

@humphd Do I need to stick with the "blue" theme?

[humphd]

Yes, this isn't about changing colour, only contrast. @agarcia-caicedo has already done colour theming in other PRs.

[humphd]

Confirmed this was fix with light theme changes, closing. Sorry Jenn, we'll find you another bug.