In the initial Dan rankings, solid red.
1st-5th Dan Black Belts wear a black belt. 6-8 wear black belts also but can wear a red and white striped belt. 9-10 wear a red belt, the highest rank ever reached. (Theoretically if one attains perfection in judo, they are 12th dan and wear a double wide belt, to distinguish from a single-wide beginners belt.)
*The ranks used in other countries including Europe use the black belt as the highest, with the order of ranks being white, red, yellow, orange, green, blue, brown, and black.
Grey is not used in belt colors for judo rankings.
Red and White belt.
Grey is not a color of judo . White and blue colored gi(dress),and belt color may different .
There is Blue Gi's and Blue belt ( 6th belt )
Black, the rank is called Shodan.
bluegrey... (If that is even a color)
It depends, for the Senior fighters, the second highest colour belt is brown, but the second highest belt is actually your 9th black belt (9th dan, this is pretty much knowing every throw, and only one person has ever reached it) Juniors, the second highest belt is blue, after brown, as you cannot be a black belt junior. :D
white (or red), yellow, orange, green, blue, brown, black, then red and white blocks (above 5th Dan). the top rank of belt is 10th dan, which is a plain white belt
The belt order goes as follows: White (Single Wide) Yellow Orange Green Blue Purple Brown Black (1-5th Dan) Red and White (6th-8th Dan, Most Still Wear Black.) Solid Red (9-10th Dan) Double Wide White Belt (12th Dan, has never been awarded. Perfection has to be attained before receiving this belt, and perfection is not possible. The Kodokan, and other judo organizations have the power to award this but never have.)
The minimum age to be awarded a black belt in Judo period is 16.
white belt
yes it is! :)