Changed visited-link and link colors in default theme to be more accessible

[Godmartinz]

Changes the visited-linkand link colors to have better contrast against the grey background color as well as be distinguishable between eachother.

Before:

After:


[sc-28469]

[what-the-diff]

PR Summary

• Updating Color of Links
  The color for links displayed on the website has been updated from a darker shade of blue to a new color (No multilanguage support for slack messages #3366). This change is expected to improve the visibility and accessibility of the links.

• Modifying Visited Link Color
  The color of previously visited links has been adjusted from a lighter shade of blue to a lighter version of the new link color (No multilanguage support for slack messages #3366, lightened by 20%). This should make it easier for users to distinguish between the links they have already clicked on and the ones they haven't.

[snipe]

This change overall looks good, but it's also changed the color of other links, like the breadcrumbs, and the blue is a lot colder. The "wrong" blue, versus the more grayish blue we use for the headerl.