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”.