yes you do
Blue then green then orange then yellow
It just means you are starting out. As you learn more and get better, you will move up in rank. Even a yellow belt can be good at a few techniques.
Black, the rank is called Shodan.
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.)
White, White-Yellow, Yellow, Yellow-Orange, Orange, Orange-Green, Green, Green-Blue, Blue, Blue-Brown, Brown, Black, Red-White, Red
The belt colors in least to greatest are: white yellow orange green blue purple brown black
A yellow belt just means they are still learning. It does not mean they are bad at it, it just means they have a lot to learn yet. They may be very good a a few techniques.
Grey is not used in belt colors for judo rankings.
White, Red, Yellow, Orange, Green, Blue, Brown, Black and (if passed Dans) Red and White
it means a warning like in soccer if you get 3 it means that the opponet gets a point
It just means you just started learning, so are not expected to be good at this stage