BLACK, BLEACH, BLEAK, Spanish BLANCO
As we can see, these words ultimately derive from the Indo- European (IE) root bhel-1 which means “to shine, flash, burn, shining white and various bright colors” according to the Indo-European Roots Index of The American Heritage® Dictionary of the English Language, 4th ed. Boston: Houghton Mifflin, 2000. www.bartleby.com/61/. [05/11/08]. The extended root *bhle -, is contracted to *bhl -. It is also suffixed form *bhl -wo-. blue, from Old French bleu, blue, and from Germanic (Gmc) *bl waz, blue. It is also explained as the extended root *bhleg- is constracted to *bhl -.with the meaning of “to shine, flash, burn”.

The original OE form of black was blæc and this root became *blak- in Germanic (Gmc). The same root produced in OE is blac which means “white, bright”, the common notion being "lack of hue." The main OE word for black was sweart. In ME it is often doubtful whether blac, blak, blake, which means “black, dark, or pale, colourless, wan, livid”.
The corresponding OE form of bleach is bleacan which comes from the Germanic (Gmc) form *blaikjan and which means “to make white”. In ME became blechen from OE bleacan.
The word bleak became bleke, probably alteration (influenced by bleke, pale) of blay, from OE bleage. In ME it became bleik, “pale”, from Old Norse bleikr, “shinning, white”. The word comes from Germanic (Gmc) *blaikaz, “shining, white”.
Some derived forms from Germanic (Gmc) are blende, from Old Norse blanda, "to mix"; blond from Germanic *blendaz, “clouded”, and *bland-, *bland-ja-, which means “to mix, mingle” (< “make cloudy”). Or also blench from Old English blencan, meaning “to deceive”; then we have blanch, blank, blanket, blancmange, which came from Old French blanc, "white". Both blench and blanch came from Germanic *blenk-, *blank-, meaning “to shine, dazzle, blind”. So in this way we can see a little development of de word black “being of the color black, producing or reflecting comparatively little light and having no predominant hue; having little or no light: a black, moonless night”, to the other one blanco as the word blanc means “white” we know that in Spanish it means “blanco”.

Other words containing the IE root *bhe-l are beluga, from Russian bely , “white”; Beltane, from Scottish Gaelic bealltainn, from Old Irish beltaine, “fire of Bel” (ten, tene, fire; see tep-), from Bel, “name of a pagan Irish deity akin to the Gaulish divine name Beleno”, from Celtic *bel-o- ;phalarope, from Greek phalaros, meaning “having a white spot”.