The amenability of various color-controlling algorithms to the real-time operator control of color stimuli was investigated. Mathematical models based on eight color spaces were employed: three uniform color spaces (L*u*v*, L*h*C*, and Y 2.2u' VI), a graphics algorithm (HLS), an opponent color model, the NTSC broadcast signals (YIQ), and two sets of color primaries. Eighty subjects, divided equally among the color spaces, were required to match colors under time-limited conditions. The apparatus employed was a color-manipulation device using LEDs, custom-built in the Displays and Controls Laboratory at Virginia Tech. The device allows for 12-bit resolution on each color channel and higher stability of luminance and chrominance over the short and long term than can be achieved with experimental quality CRTs. / Master of Science