The precise medical term for color blindness is Deuteranopia
(aka Red-Green Color Blindness)
Via Colour blindness.com
Deutan color vision deficiencies are by far the most common forms of color blindness. This subtype of red-green color blindness is found in about 6% of the male population, mostly in its mild form deuteranomaly
The article then elucidates that only 0.35% of the female population suffer from deuteranomaly. The two following photographs compares the perception of colour between someone with normal colour vision and someone with deuteranopia.
An example of "normal" vision and on the right "deuteranopia" vision
In 1794, John Dalton published his first scientific paper which he called: Extraordinary Facts Relating to the Vision of Colours. Dalton was the first scientist to realize that the condition was hereditary because he and his brother had the same disorder.
The British website QI (Quite Interesting) describes the first time John Dalton understood his vision was not similar to others.
[...] At the age of 26 he bought his elderly mother a pair of stockings for her birthday, which he didn't realise were scarlet. As a devout Quaker she was expected to dress soberly so this caused a miniature scandal in the family - which Dalton was initially at a loss to understand, as he thought they were blue. His brother couldn’t see what the problem was, either – Dalton’s first clue to the genetic nature of colour-blindness. He had a similar problem later in life, when he scandalised fellow Quakers by wearing a scarlet academic gown at an audience with the King; he thought it was grey.
So it was not until Dalton was twenty-six did he realize that he could not distinguish shades of greens and reds, and when he had made this self-discovery he did not know what this condition was called, no one had coined the term that English native speakers know today, colour blindness. The author of John Dalton and The Rise of Modern Chemistry (1901) explains:
It seems almost incredible that Dalton should have lived to the age of twenty-six without noticing this peculiarity; and yet it appears less strange when we remember that thousands of persons have, probably since time was, suffered in a similar
manner without knowledge of their infirmity; and, indeed, Dalton was almost the first to direct the attention of the scientific world to the subject.
Dalton himself described it as “the infirmity of my eyes” (p.73) The author, Sir Henry E. Roscoe, clearly states that the term colour-blindness is owed to David Brewster (which @Sven Yarg's answer also mentions) but Roscoe initially expresses perplexity on its appropriacy:
Elie Wartmann, of Lausanne, and Prevost, of Geneva, investigated the peculiarity in question, to which they gave the name of "Daltonism" [...] George Wilson, whose researches on this question were published in 1855, proposed the name “Chromato-Pseudopsis,” or false-colour vision. This is certainly a more correct term, though rather a jaw-breaker. Herschel coined the word “Dichromic,” or “two-coloured” vision. But this does not fit the case exactly, because most “colour-blind” eyes can distinguish three colours, and, like Dalton, they see differences between red, yellow, and blue : so that after all the term; “colour-blindness” is perhaps the best that have been proposed.
It therefore appears that the term, colour-blindness, was not invented on the fly and there is no evidence to support its existence before Dalton had published his paper in 1794.
First Recorded Instances
The simplicity of colour blindness, as an English expression, might lead one to imagine it already existed in the early 19th century. Unfortunately, there are no traces of colo[u]r blindness recorded by Google Books between 1700 and 1840. The three dates mentioned in the link are all errors. The first snippet dated 1766, is clearly an OCR error. The second, The Edinburgh Review: Or Critical Journal - Volume 207 was printed in 1908. And the third from The Nautical Magazine, Volume 50, was not printed in 1832 but in 1881.
I repeated the procedure with colour blind covering the same period, among the many false positives I found the following instance from Extracts from Longman's Magazine - Page 161, which appears to be dated 1833. However, it has been pointed out by Sven Yargs (in the comments) that the correct date is 1889.
Notwithstanding, the excerpt is noteworthy because it highlights one of the major drawbacks of being colorblind, namely the impaired ability to interpret railway signals.
A man who is colour-blind is, by necessity, prohibited from taking charge of railway signals; yet over and over again we see youths whose emotional natures are quite as strong a bar to some calling or profession—such a profession as mine, for instance — forced into the selected profession, to endure a martyrdom for life, with not one moment of chance for distinction, or for anything more than the qualified performance of duties which are a daily cross and a daily sorrow.
In fact, many English texts published after 1840 mention colour blindness in connection with engineers and railway signals.
Signal colours were first investigated scientifically and with respect to colour blindness in 1855 by Dr. G. Wilson of Edinburgh. He concluded that red and green were poor choices, because: (1) red in shade tended to black; (2) red and green were complementary and did not contrast strongly, and each was the fatigue colour of the other; and (3) about 1 in 50 males could not distinguish them, especially in dim light.
Early Railway Signals
In conclusion, the expression “colour-blind” seems not to have been inspired by German, I found not a shred of evidence in support of this idea, it was instead a neologism created by the Scotsman, physicist, mathematician, astronomer, and inventor Sir David Brewster (1781 – 1868).
Jan Dirk Blom A Dictionary of Hallucinations