overlapping light sums wavelengths; more light → toward white.
Beam / wash
a defined shaft of light vs. broad soft coverage.
CCT
correlated color temperature; where a white sits on the warm-cool axis, in kelvin.
Complement
the hue opposite on the wheel; maximum contrast partner.
CRI / TM-30
color quality metrics for light sources; TM-30 (IES) is the modern, stricter one.
CTO / CTB
orange/blue correction gels for shifting color temperature.
Gel
the colored filter sheet in front of a lamp; also the name of this app. Standard ranges: LEE (L-numbers) and Rosco (R-numbers) — e.g., L201 Full CT Blue, L181 Congo Blue.
Gobo
a stencil in a fixture that shapes the beam into a pattern.
Haze
fine airborne particles that make beams visible by scattering.
Metamerism
two colors matching under one light source and splitting under another.
Pixel mapping
driving many LED fixtures as pixels of one image (e.g., Madrix, Resolume).
Saturation
color purity; full-sat cuts through haze, pastel washes out.
Subtractive mixing
pigments/filters absorbing wavelengths; more filtering → toward black.
UV / blacklight
long-wave ultraviolet; invisible itself, makes fluorescents glow.