What it shows:
The full spectrum of colors (including white) in a television picture is produced by the additive mixing of only three colors: red, green, and blue.
How it works:
In a color television tube, three separate electron beams are focused so as to strike the appropriate phosphor dot on the screen. By looking at the television screen under considerable magnification, one can clearly see that there are only three phosphors which are stimulated by the electron beam(s). The apparatus is diagrammed below.
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