Hi there,
I appear to have gone grey since e lockdown
but only in one single streak on one side 

I was considering doing a semi-permanent dye just on that section, to see if I can make it look natural enough before I go back to work, and my question is does she come ready mixed so I could just use a bit, or do you have to mix it before use so I wouldn't be able to save the rest of the bottle for later?
Can anyone recommend an easy, good dye for this, especially if you know one that is ready mixed and ready to go.
Sorry if this is a weird question, I have vague memories from my teenage years of having two bottles that need to be combined... thanks for any tips!