A system may produce images including narrow-bandwidth colors. One or more sets of the narrow-bandwidth colors may be selected to be interpreted as substantially a same color by a user. The system may include a light source configured to produce the narrow-bandwidth colors, and/or narrow-passband filters may create narrow-bandwidth colors from light emitted by broad-spectrum light sources or color sources. Spatial and/or time multiplexing may be used to create separate narrow-bandwidth colors interpreted as substantially a same color by the user. The light source and/or the narrow-passband filter elements may be adjustable and may alternate between emission of two or more narrow-bandwidth colors. A viewing device may include filters configured to selectively filter the narrow-bandwidth colors. The user may filter the narrow-bandwidth colors to separate a stereoscopic image pair, to view an image specific to a user, to view desired content obfuscated by an obfuscating image, and/or the like.