Black and Blanco (white) Are The Same, and..

 ...blue, bleach, blush, blond, flame. That's a lot of colors from the same root word *bhel-, meaning "to shine, flash, burn." But that's only the beginning. Blank is from the same root, and it is amusingly disputed whether the surname Blake meant "person of light complexion" or "person of dark complexion." 

According to the Oxford English Dictionary, "in Middle English it is often doubtful whether blac, blak, blake, means 'black, dark,' or 'pale, colourless, wan, livid"

Then there's all the flame words like flamingo, inflammable, or the lightning words like fulgent. Or Phlegm and phlegmatic; phlox. It gets worse.  the same root gives us Latin flavus "yellow," Old Spanish blavo "yellowish-gray" and Welsh blawr "gray." How does one root give us such a variety of colors?

The key is in the last *bhel- entry, "burn." We can see the connection to shining, and thus to lightning, and then to light in general. But the same associations do not take place in all tribes over time.  One group goes east and increasingly uses the burning colors to think of lightning, light, and the sky.  Farther out, that becomes blue or gray. Another group goes west and keeps the associations with things that have been burned and are black or dark, and possibly blank or the absence of color. A third group goes south and keeps the ideas of flame and redness. The group that goes north gets to yellow, but whether they got it from leaden, gray-yellow skies or from bright flame (as opposed to embers) ends up being argued over by the people who study such things.