As in many roguelikes, color plays a major role throughout Tower of Doom. Color is the only way to distinguish between different types of the same magic item, and knowing which items are helpful and which are harmful is a crucial part of gameplay. Color is also used to indicate the strength of a hand-to-hand weapon, the number of shots available from a projectile weapon, and the value of a treasure.
Except for food (which is always brown), every inventory item in Tower of Doom can be one of eight colors. These colors are drawn from hex values 0x08 through 0x0F in the Intellivision's 16-color palette, and are as follows:
For weapons and treasures, this sequence of colors mirrors their value, from least to most. In other words, gray treasures are the least valuable, and magenta treasures are the most valuable; a brown projectile weapon has fewer shots remaining than a pink weapon; and so on.
For magical artifacts, there is no linear relationship between an item's placement in the above list of colors and its value. For example, a gray Potion Bottle is a healing item, whereas a pink Potion Bottle is harmful. However, cyan magical items are usually harmful, and magenta items tend to be extremely powerful.
These colors apply when playing the Novice, Tower, or Challenge adventures, and when using most characters. However, when using the Waif or Barbarian characters, or when playing the Catacombs, Fortress, Wizard Hunt, or Grail Quest adventures, the overall relationship between items and colors is randomized, and the color assignments will be different in every game.
All categories of items are subject to the same color substitutions, which makes life much easier. For example, protection against fire is normally given by the orange Potion Bottle, and the orange Ring enhances your character's defense. If you're adventuring in the Catacombs and find that fire protection has now been assigned to the pink Potion Bottle, you now know that, for this playthrough, the pink Ring will offer enhanced Defense.
Furthermore, the colors aren't truly randomized, but are simply rotated by adding a fixed number to the color value, mod 8. In other words, the game doesn't change the order of the colors, but treats them as if they were on a slide rule. So if a item you know is Cyan appears to be Gray, then that means that:
- all items that appear Gray are actually Cyan,
- all items that appear Cyan are actually Orange,
- all items that appear Orange are actually Brown,
- all items that appear Brown are actually Pink,
- all items that appear Pink are actually Lavender,
- all items that appear Lavender are actually Bright Green,
- all items that appear Bright Green are actually Magenta, and
- all items that appear Magenta are actually Gray.
And since there are only eight colors, there are only eight possible rotations, including the "normal" one.
Thus, a clever player who's embarked on an adventure with scrambled colors might start out by deliberately wasting a strong projectile weapon. As the weapon runs out of ammunition and changes color, the player can see what sequence of colors is being used on this playthrough, and thus can know the strengths and functions of all items in the game without having to test them individually.
Even easier is simply to glance at your starting items. If you're a Waif, your boot is normally Magenta before the color-scrambling process. So if your boot instead appears to be pink (for example), then you know that a "pink" flask you find is actually a powerful Magenta Flask of Superpower -- and you also know that a "green" Book is actually a Cursed Cyan Book, a Bottle that appears orange is actually a valuable Lavender Bottle of Sight, and so on.
Finally, there's a 1-in-8 or 12.5% chance that the game will simply leave the default colors alone, so if you're lucky you can get help with a difficult Adventure (or a weak character) when the game shows its "true colors".