Console altar colours
black
blue
green
cyan
red
magenta
brown
lightgrey
darkgrey
lightblue
lightgreen
lightcyan
lightred
lightmagenta
yellow
white
(The actual colours that these map to are terminal-dependent, so don't take my hex codes as exact.)
Of these, black should never be used (since it's the background colour; a black character means "unexplored"), and darkgrey means out-of-LOS. Furthermore, the game semi-recently changed to disable darkgrey by default and use blue in place of darkgrey. This leaves us with only 15 usable colours, and only 13 good usable colours for dungeon features, since two of them should really be reserved to indicate the feature is out-of-LOS. (This is violated by quite a few bad vaults, and in the case of blue by many monsters and deep water, but...)
All altars are represented by the same character, _. There are 26 altars in the game. You cannot unambiguously represent 26 different features with only 15 colours to choose from, let alone only 13.
The game currently tries to sidestep this by using "elemental colours", which are colours that change on every redraw. For example, the "fire" colour is randomly red, yellow, or lightred. But this doesn't really help because the screen doesn't continuously redraw (nor should it); when you find a red altar it could be Trog's or it could just be Uskayaw's or even Xom's.
Obviously the long-term goal should be to reduce the number of gods below 13, but until then, I think another arrangement should be found, for the benefit of console players.
The only real solution is to use two different characters for altars. The obvious candidate is '-'; it's visually distinct from '_' without being a different shape, and it's not used for anything else except tentacle segments, which are unlikely to be confused with altars (and, in any case, already share glyphs with wands and staves). However, I admit this is a bit confusing and aesthetically displeasing.
The only alternative I can think of is to show in-LOS altars and their corresponding gods in the monster list...
Failing any of that, there are some weaknesses in the existing altar colours:
- Uskayaw's altar uses red and magenta, which are barely distinguishable at a glance. It's really easy to mistake for a Trog altar. The magenta should be changed to lightmagenta (lightred is overused already).
- Wu Jian and Qazlal altars have too many colours. They are very hard to distinguish from Xom altars. Qazlal's altar in particular is subject to some fairly complex animation behaviour that is completely unnoticeable to players.
- Vehumet's altar has a similar problem to Uskayaw's altar but reversed (it uses both lightred and lightmagenta). While these two colours are much more distinguishable than the dark versions (on reasonable terminals) there's not really any reason for Vehumet to use them in the first place, because:
- Plain lightgreen, lightblue, and lightgrey are not used on any altar, and their use in altar elemental colours is very minimal - they are mostly for Jiyva, Vehumet, and faded altars. Why aren't these altars just plain lightgreen, lightblue, and lightgrey, respectively, instead of hogging those colours AND polluting other colours too? (UPDATE: I'm wrong, Hep and Zin)