Color arithmetic (ConceptTopic, 7)

<[#ontology [kind topic] [cats Color Math]]>
'''Color arithmetic''' is a system that seems to baffle many people, even though it is extremely logical.

It goes like this:

<table class='wikitable'>
<tr><th colspan='4'>-> Light -></th></tr>
<tr><th>Empty</th><th>Primary</th><th>Secondary</th><th>Full</th></tr>
<tr>
<td style='width: 8em; text-align: center;'>Black</td>
<td style='width: 8em; text-align: center;'>Red<br />Green<br />Blue</td>
<td style='width: 8em; text-align: center;'>Cyan<br />Magenta<br />Yellow</td>
<td style='width: 8em; text-align: center;'>White</td>
</tr>
<tr><th>Full</th><th>Secondary</th><th>Primary</th><th>Empty</th></tr>
<tr><th colspan='4'><- Pigments <-</th></tr>
</table>

You can easily read off the chart that, for example, '''magenta''' is a '''primary''' color of '''pigments'''.

When combining two primary colors to make a secondary color, you move in the direction of the arrows, and choose the color that is not on lines you already chosen. So when dealing with '''light''', '''red''' (line 1) + '''green''' (line 2) makes '''yellow''' (line 3); when dealing with '''pigments''', '''cyan''' (line 1) + '''yellow''' (line 3) makes '''green''' (line 2).