Interestingly, even Daltons very first paper already arrived upon this 8% number:
...it is remarkable that, out of 25 pupils I once had, to whom I explained this subject, 2 were found to agree with me... However, despite his accuracy, the number varies among groups. Isolated communities with a restricted gene pool sometimes produce high proportions of color blindness, including the less usual types. Examples include rural Finland, Hungary, and some of the Scottish islands. In the United States, about 7 percent of the male population—or about 10.5 million men—and 0.4 percent of the female population either cannot distinguish red from green, or see red and green differently from how others do (Howard Hughes Medical Institute, 2006). More than 95 percent of all variations in human color vision involve the red and green receptors in male eyes. It is very rare for males or females to be "blind" to the blue end of the spectrum. History
During the 17th and 18th century, several philosophers hypothesized that not all individuals perceived colors in the same way:
...there is no reason to suppose a perfect resemblance in the disposition of the Optic Nerve in all Men, since there is an infinite variety in every thing in Nature, and chiefly in those that are Material, tis therefore very probable that all Men see not the same Colours in the same Objects.
M*
(as subscript), mutated M opsin. L*
(as subscript), mutated L opsin.The following table shows the pattern of inheritance for congenital red–green colorblindness (protan/deutan) given affected, unaffected or carrier parents. When daughter 1 and daughter 2 (or son 1 and son 2) differ, this indicates a 50% chance of each outcome. Some conclusions from the table include:

A male cannot inherit colorblindness from his father. A colorblind female must have a colorblind father. A female must inherit colorblindness alleles from both parents to be colorblind. Colorblind females can only produce colorblind males. Because carrier females often have a colorblind father, colorblind males often will have a colorblind maternal grandfather (or great grandfather). In this way, colorblindness is often said to skip a generation.Note: these conclusions do not apply to other forms of colorblindness (e.g. tritanopia). Genetics of blue–yellow color blindness
Blue-yellow color blindness is a rarer form of colorblindness including tritanopia/tritanomaly. These conditions are mediated by the OPN1SW gene on Chromosome 7. Other genetic causes
Several inherited diseases are known to cause color blindness:

achromatopsia(also called rod monochromatism, stationary cone dystrophy or cone dysfunction syndrome)
cone dystrophy
cone-rod dystrophy
Lebers congenital amaurosis
retinitis pigmentosa(initially affects rods but can later progress to cones and therefore color blindness).They can be congenital (from birth) or can commence in childhood or adulthood. They can be stationary, that is, remain the same throughout a persons lifetime, or progressive. As progressive phenotypes involve deterioration of the retina and other parts of the eye, many of the above forms of color blindness can progress to legal blindness, i.e.