Colorblindness, or more accurately color vision deficiency, mostly affects men and tends to run in families. As many as one in 12 men has some degree of this condition, as compared to about one in every 250 women. Besides difficulty with red-green perception, some people have other color vision problems, such an inability to distinguish yellows from blues. In very rare cases, a person may be truly colorblind and see only shades of black and white. These may actually become slightly harder to distinguish.
Greens fall in the middle and are less noticeably affected.
When Siciliano first tried the lenses, he could instantly see many more variations in shades of color. You say, 'OK, that's red,' and work from there. Many eye experts are similarly cautious. I don't have the clinical trial information, although I've asked for it. I'm not going to be convinced of anything until the ColorMax researchers publish a paper on it.