It is a bit better here on Discourse Meta, but I’m pretty certain we’re using default colours on the Python Discourse.
Hyperlinks
On the Python Discourse, hyperlinks are blue #306897 on grey #222222, which has contrast ratio 2.69:1, and is below the W3C’s Web Content Accessibility Guidelines (AA level: 4.5:1, AAA level: 7:1).
(Here on Discourse Meta it’s a bit better: blue #0F82AF on same grey #222222, ratio 3.61:1, but still below AA and AAA.)
Code blocks
On the Python Discourse, the code blocks fix has been deployed now, and it’s definitely a big improvement.
But blue #4288C3 on grey #3F3F3F at 2.77:1 is still below WCAG guidelines, so room for improvement.
(Here on Discourse Meta, blue #4288C3 on grey #3F3F3F at 4.34:1 is similarly better but below AA and AAA.)