Alfaparf 11.11 with 20 too light, need to go one shade darker

[Maria61]

Hey all! I dyed my hair with Alfaparf Evolution of the Color 11.11 with a 20 developer. I want to get highlights later in the summer so feel this base color is too light.
I want to go down to AEC 10.11 but don't know if I should apply it with 10 or 20 developer.
Please help!

 

[AcidPerm]

At you a qualified hairdresser?
What’s your natural base and what level are you looking for?

 

[Maria61]

At you a qualified hairdresser?
What’s your natural base and what level are you looking for?

My natural base is very dark brown and need to use ash tones to avoid brassiness. I love the blonde but it's too light for the coming summer and highlights. I was advised to apply 10.11 with 10 developer to bring it down one tone but want to make sure.
Thanks!

 

[AcidPerm]

Sounds like you need to visit a good colourist to advise you properly.

 

[Maria61]

Sounds like you need to visit a good colourist to advise you properly.

Quite honestly? Don't have the money. My hairstylist was charging me $80 just to color my roots! I can't do it.
I'll accept anyone's input and appreciate it.

 

[Noodle]

Quite honestly? Don't have the money. My hairstylist was charging me $80 just to color my roots! I can't do it.
I'll accept anyone's input and appreciate it.

If cost is an issue, then look for a local training college, where the students are supervised and the costs are discounted.