I found a graphic detailing belt colours according to ranks. In there, the last two judo ranks are red and white for 6-8th dan ranks and full red belts for 9 and 10th dan.
Is the highest judo belt really red? I thought it was black...
It is, and it takes a LONG time to reach.
If you ever reach your 9th Dan, you get a red belt to wear. The white-red belt is gotten at the 6th Dan.
But at this stage, you need to wait between 8 or 10 years between each test. And it's not automatically given to you ... the internal federation will only give the highest Dan to people who actually have an impact on judo as a whole ... in the history, there have only been 15 people who were awarded a 10th Dan.
In Canada there have been only 4 poeple with a 9th Dan: Raymond Damblant, Hiroshi Nakamura, Yeiji Inouye, Yoshio Senda. Dr.Senda was the 1st ever, and died in 2009.
To add to the (excellent) answers already provided:
Black is an arbitrary color for an arbitrary level. This is why I've told people to be very, very dubious of special "black belt tracks."
There are two reasons for this:
First, "1 dan" (or its equivalent) is an arbitrary designation within the art. It indicates that you have learned whatever set of principles they think you should know to be whatever they consider a 1 dan. This isn't flippant: It is part of why some arts get you to "1 dan" relatively quickly where others it can take years and years to get there.
This means that while comparing 1 dans within a single art is fairly effectively, it breaks down somewhat even between schools in the same art and almost entirely when you transition between arts.
The second reason is that, even within different schools within the same art, they will use different belts. I've seen a "brown belt" and a "red belt" mean the same kup rank simply because the organization as a whole had no prescription and the individual schools used different belt color ordering.
Basically what it boils down to is that if an individual is a "black belt" or a "red belt" it doesn't mean a whole lot without knowing how long it takes/what it takes to get there and where that particular school/tradition considers that belt color in whatever ranking system they use.
…which of course all assumes they even use a graded ranking system and that it is represented by belts, neither of which are even entirely universal.
Yes it is.
It actually goes Black -> Red White -> Red
Those Upper ranks tend to be more about service to the art.
You are correct. Red belts are the highest level that one could obtain, 9th Dan being the highest level a normal person could become and 10th Dan which is reserved for the Head of the foundation or Ex Heads..
Usually for 3rd DAN and above, any promotion would no longer be based solely on your technical skills, but by your contribution to the JUDO society. Contributions such as organizing international Judo events in your country, participating in international seminar or competitions, and other activity that would uplift the image of JUDO.
Mind you these were verbal explanation of my sensei who's a 5th Dan belt holder.
Aside from that, Judo and BJJ also share similar belt grading system and according to the official belt ranking system, if you obtained your black belt at the age of 19, you would only be getting your 9th dan belt (Red) at the age of 67yrs old.
Quoting the Super Awesome BJJ Foundation:
To achieve 10 Dan status under traditional Judoka lineage from Japan can only be awarded by Soke Kano's grandson/descendants . Judan is the most difficult level ever, and VERY few from the Kano line have achieved that over the last 120+ years.
Other International organizations have acknowledged or promoted a 10th Dan level outside of Kano.
The Red colour is used to show the intense desire to train and the sacrifices made in achieving it. Since getting a white/red or pure red belt meant you invested a large portion of your life to your chosen art.
Also a lot of (Japanese Martial Art) systems theoretically have unlimited rankings so there could be 11th or even higher DAN ratings. It is just that no one has ever achieved it. :-)
But different organisations have different rules about what ranks you could achieve and what the requirements are. But all martial arts using this system got it from JUDO.