This fix should now be available after a page refresh.

This does NOT yet appear to be fixed for me. Clearing cache does not change anything.

I’ve tried loading wiki pages and issue trackers on two different workstations (located in different states), using both my main Chrome browser and a second browser that I haven’t used in weeks. All of them still show the defective grey-on-white text.

I just tried, the fix doesn't work at all.

same unreadable pages for both wiki and issue tracking

We've implemented a fix for this issue that should be released today. I'll update the thread here once it's been successfully deployed.

57b7f67f3625, I've cleared my browser's cache (specifically Cached images and files) and performed a force refresh (Shift+F5), and I'm still seeing the same thing in my issue tracker. I also confirmed the same behavior in a browser that I haven't even opened in several months, so it's definitely not a stale cache. Is it possible that this hasn't been rolled out into all instances yet? 

This has been confirmed as a bug by our development team and has been rolled back accordingly. The fix will be deployed for this issue within the next 24 hours.
UPDATE: A fix has now been deployed, please clear your browser cache/perform a refresh as this should be resolved now.

Is this the reason why we got unreadable page ??

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yes, fixing the problem on issue tracker is more important than on wiki.

Hi Ben - Thanks for entering this ticket, and confirming the problem affects all BBC wikis service-wide.

As such, I disagree with your assignment of "Severity Minor" and "Medium priority". This is a regression that makes all Bitbucket Cloud Wikis and Issue tracker content pages basically unreadable. For many BBC repos the wiki and/or issue tracker are the main landing page for repo web presence, and an unreadable page means the wiki and issue tracker services are effectively down as far as Bitbucket Cloud web visitors are concerned.

Whatever Bitbucket change on Jun 28 was responsible for breaking web page rendering should never have been deployed. Now that the problem has been confirmed, it should be immediately rolled back without further delay.

Please escalate the severity and priority of immediately reverting the changes that caused this regression. 

Please note that the problem also affects the Bitbucket issue tracker – arguably a more significant issue for projects that use that as the primary issue tracker – so it's not limited to just the project wikis.