Colourful eggs (not colorful) are Easter eggs that appear on Easter Day (April 3rd) and lasts throughout the Easter week (April 3rd - 11th/Sunday). The main screen of the game will show falling colorful eggs in addition to the usual falling white eggs.
A barbarian stumbled over a colourful egg.
These eggs will appear throughout the dungeon (though only in unexplored regions) in addition to normal eggs and satiates a tiny bit of hunger (30 calories) and will yield a random surprise item, ranging from gold to even large chests with items in them. The state of colourful eggs does not seem to apply to the items within them -- a cursed colourful egg may contain uncursed or even blessed items. Regardless of its contents, all colorful eggs weigh 24 oz.
Identification reveals the item that is hidden inside, e.g. an uncursed sky blue potion egg.
The colourful eggs may be used as pie ingredients at the bakery, however results appear to be buggy as the resulting pie will have the names such as %i pie and the item will be lost if eaten by the player.