Mixing colours

Hi Jess,
That's a tough question.

They are many rules to know and it's quite difficult to tell you in only one answer. The art of coloring takes a lot of practice.
But I try to explain you as briefly as possible.

First: whith grey hair and washed out hair, you must mixt 1/2 basic color and 1/2 color with reflect.
For exemple: 1/2 of 6.0 + 1/2 of 6.31 otherwise the color will go off soon and grey hair won't be cover propely..

Secondly: if you don't have the special color you need, you can do a mix.
For exemple: you need to create 7.1 so you can do 8.1 + 6.0

Thirdly: if you have a haircolor too different with the result
For exemple: your customer has a coppery color (6.04) and the result she wants is a chocolate brown (5.32)
you can do 5.0 + 5.32 + 5.1
When you go darker it's better to mix a basic color (5.0) + the color of your choice and cancel the copper with it's opposite : blue wich is ashy 5.1 (see the color wheel sheme ).

Forthly: if you want to boost a color who goes off rapidly you can had more pigment in it.
For exemple a beige 8.2 you can add 1/4 of 0.2 or pure beige in your bowl.

At last but not least, you can do so many different shade to lighten up or strengthen a reflect by mixing colour.

They're is not a special receipe that goes for everybody. It's all about the actual hair color you have to work with and the result you want.

I advise you to write down every mixing of colour you do for each customer. Your choice for the next color will be much easier.
By practicing you will be more confortable with the process ;-)

If you need further precision feel free to ask me!
Have a great experience with the art of hair color!