Mix docs silent on weight endpoints

[pnorman]

The mix docs are silent on if a weight of 0 is 100% of the first colour or 100% of the second colour. Also, no examples are other than 50%.

[seven-phases-max]

Yep, that's missing (usually, when developed by descendants of Greek/Roman civilizations, the assumed default direction is left-to-right/clock-wise, thus 0% -> full left/first/A-color, 100% -> full right/second/B-color).