Within Motoha Yoshin Ryu JuJutsu, the Japanese do not use a coloured belt system or perform gradings until Shodan (Beginner Dan, often referred to as 1st Dan). Those training start wearing a white belt and transition directly to black if they pass the grading.
The concept of coloured belts and gradings before black belt level is generally a western, modern addition to many martial arts, with each style often having its own different choice of colours and progression between these.
Many people consider the black belt to be something awarded to an expert, one who knows everything - in reality, the first black belt within MHYR is taken in the literal translation of the term 'Shodan' which means 'beginner Dan' - someone who has sufficient experience in the concepts of the style to be taught the more advanced and higher level aspects to techniques as well as new kata. In contrast, 2nd Dan, called Nidan, does translate to 2nd Dan more accurately, as do the higher Dan levels including:
In the UK, we have the following coloured belts before 1st Dan:
The requirements for each differ between juniors and adults, and the expectation of what a junior belt must achieve does not reflect that expected from an adult of the same belt colour. We do not teach certain aspects of techniques to juniors due to risks to joints, so for example, many of the locks are removed.
You do not always have to progress through each colour; with sufficient skill and effort it is possible to skip to the appropriate belt for your abilities, however only Soke can award Dan grades.
Junior Dan Grades can only be awarded at Soke's discretion, generally Dan grading's are for those who are 16 years or above.
Overall, everyone learns at different rates, so we have no fixed time between belts and gradings providing students attend regularly and put in the appropriate amount of effort during training!