After Canada and the U.S., Samsung's "fix" for the red screen tint issue affecting some Galaxy S8 owners is now rolling out to unlocked handsets in the UK. The update to software version G950FOXM1AQDG and G955FOXM1AQDG, for the S8 and S8+ respectively, started rolling out on unlocked S8 models this morning. The update weighs in at 426MB, so it's likely Samsung has bundled other minor fixes into the OTA.
According to Samsung's official changelog, the update brings "improved color optimization and convenient color adjustment" — which translates to a fix for whatever was causing some S8 displays to show a reddish hue, and an easier way to tweak the overall color balance in the Display Settings menu.
For what it's worth, the Android security patch level remains unchanged on 1 April 2017 — no sign of that May security patch yet.
And it's worth remembering that carrier-branded Galaxy S8 phones will likely lag behind today's unlocked rollout by a few days or weeks.