Darken Red Player HP Bar

[Deimos]

Problem: It is difficult to see the position of the HP bar when you are at red HP.
Reason: The red value used for missing HP is too close to the red value used to indicate low HP.
Fix: Darken the value used to indicate low HP.

Current vs Suggested

[Arrhythmia]

I honestly can't tell the difference between the two pictures you posted, but I still think it's a good idea. What if the background of the HP-bar was changed to black? Or just transparent?

[Deimos]

That's currently the way opponent HP bars work. I thought about it, but it seems that if you had extremely low HP, it might look like the HP bar has completely disappeared. This also happens when you're at full HP, so it could potentially confuse someone.

[and into]

The remaining HP (smaller bar on the left-hand side of the total HP bar) is a bit darker in the image on the right. It does help visibility a bit IMO.

[dck]

Oh hey giant geckos look a lot more funky than I thought that's great.
Do not ruin them bloax.
(this is GDD relevant because not having coconut geckos is better for the game)

[Tiber]

I agree with the problem, but your fix doesn't go far enough. Magenta is already used to show dangerous items, so I would use that color.

[johlstei]

A border with a light color for contrast would help I think. Have it go around the outside of each bar, and also down where the split is.

[Igxfl]

I agree with the problem, but your fix doesn't go far enough. Magenta is already used to show dangerous items, so I would use that color.

I think red is for dangerous items and magenta is for ambiguous items.

[XuaXua]

Orange for health, to contrast Blue for magic.

[Zicher]

ToME solves this issue by applying a red-ish "tint" to the whole screen whenever under 50% HP, with the tint more intense the closer you are to die.
I do not know whether and how much this is applicable to Crawl (especially with Webtiles in mind), but it may help at least as an inspiration.