Focused links have low contrast

[cfq]

Links don't have good contrast against $focus-colour when they're in focus, it's currently 4.07:1. Keyboard users who have low vision would notice them. Screen magnification and keyboard users whose zoom follow keyboard focus would find it hard if they need high contrast.

We can fix it by setting the link colour on focus to be the same as $text-colour.

Current:

Proposed:

[edwardhorsford]

Since it's very close to being acceptable, I wonder if we could just go with a slightly darker version of link colour? The black looks rather different, whereas a darker blue isn't that noticeable.

Example:

Edit: might want to pick a colour rather than simply using sass to darken. The darker version is not saturated enough - manually picking we could get colour that perceptually is the same.

[quis]

The blue and orange isn’t a good colour combination because of chromostereopsis.

[robinwhittleton]

I don’t mind the black, but it does cause another problem: it’s impossible to tell whether the currently focused link has been visited.

[edwardhorsford]

@trevorsaint has pointed out that the contrast is poor on our service names when focused.

Example:

Suggest the solution here is to make the service name black when focused - it then matches the proposition links that are already black.