Quote:
Originally Posted by kas_1611
Can't quote for anyone else but in my forward nav lights with a warm white LED bulb there is NO colour overlap or mixing. Trust me I'd know if there was as I would not be able to see the lights, yes my colourblindness is that severe.
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A follow up note.
To those who are not red/green colorblind, review the image below to get a sense of what it is like to be such; now imagine driving or navigating with that impaired vision. Now imagine that the oncoming helmsperson or driver is colorblind. Yeah, kind of intimidating and confounding.
Don't presume that they can differentiate your navigation lights, or the traffic lights, or at least presume such at your own risk. Also recognize such limitation as to differentiating by color the lines on your vessel.
The choice of using Red and Green for signal indicators on traffic signals and navigation lights, and marker buoys is pretty much the worst combination possible because there is a significant portion of the population that has colorblindness so as to not be able to differentiate between the two colors. At least buoys have different day shapes associated with their different colors and meanings. Ditto as to the inappropriateness of the use of red and green for
electrical polarity indications, zero difference in color to such a person. FYI, out of courtesy to colorblind persons, do not use red and green
images or graphs in a presentation or publication, you will have failed in your communication if you elect to do such, that be Your choice, Not theirs. The onus is on the communicator. Reading maps can be very challenging when there is red writing or symbols on a green background. And as to hunters wearing red so as to stand out against green shrubs, well that combination makes for great camouflage.
Truly one of those "What were they thinking" issues. Who ever the They were. Obviously, not including the assessment of anyone who is red green colorblind.
My dad and my nephew, were / are, red green colorblind. I
recall my Dad telling me that he memorized the colorblindness test for the US Army Air Corp because he wanted to be a pilot upon enlisting in January 1942; he did not become a pilot because the Army Air Corp chose instead to send him to Officer
Training School [OTC] and he made a full career with the US Air Force. His approaches to traffic lights, particularly when driving at night could be quite the challenge for him; Is it red or green? Or worst perhaps is a single light flashing red or flashing yellow. If in doubt, he chose to stop and then proceed with caution. And of course his
clothing choices made for some, "Uh Dad, don't get dressed with that combination."
In an
emergency, imagine trying to instantly determine which is the Red Stop button on the
control panel of a machine, or an
electrical panel.
FYI.
The most common form of color blindness is red-green color blindness. With this condition, the gene is passed from the parent to the child on the X chromosome.
Globally, 1 in 12 males and 1 in 200 females are colorblind.
Current research states that color blindness affects roughly 8 percent of Caucasian males. According to a large multiethnic studyTrusted Source from 2014, color blindness also affects:
1.4 percent of African American males
2.6 percent of Hispanic males
3.1 percent of Asian males
0-0.5 percent of all females
Red/Green colorblindness is also known as deutan colorblindness, deuteranopia, and Daltonism.
The gene for red-green color blindness is an X-linked recessive gene. X-linked recessive genes are expressed if they’re present on both X chromosomes in females, and on one X chromosome in males.
Genes explained
a child born female would need to inherit two X chromosomes with the carrier gene to be born colorblind
a child born male only needs to inherit one X chromosome with the carrier gene to be born colorblind
Color blindness isn’t common in females because there’s a low likelihood that a female will inherit both genes required for the condition. However, since only one gene is needed for red-green color blindness in males, it’s much more common.
A bit of historical context: The term "Daltonism" is derived from the name of the chemist and physicist, John Dalton (1766-1844). Dalton was born in a village in Cumberland,
England where his father, Joseph, was a weaver in poor circumstances. He was educated by his father and John Fletcher, teacher in a Quaker
school. When Fletcher retired in 1778, Dalton took his place. In 1793 he was appointed teacher of mathematics and natural philosophy at New College in Manchester. In 1803 he put forth the facts embodied in his law of partial pressures: the pressure of a mixture of gases is the sum of the pressures which would be exerted separately by the several constituents if each alone were present. Dalton's reputation largely rests upon his great Atomic Theory. Dalton described his and his brother's affliction of colorblindness with defective perception of red and green in the first scientific paper he published. It was entitled "Extraordinary facts relating to the vision of colours, with observation" (Mem Literary Philos Soc Manchester 5: 28-45, 1798). It is the first recognized account of red-green colorblindness.
"So now you know the rest of the story."