I have many times colored my hair in years past. I always used miss clairols blondest beige and it always turned out fine. About 4 years ago I grew it all out my natural color. Light light brown (dishwater blonde)
Anyway.. last night..
I decided to color my hair
I bought lightest golden blonde ( gold base)
Instead of the blondest beige( blue base)
It is WAY too brassy
I am experienced with doing this.. and I didn't fry my hair last night or anything..
I did use a 40 developer..
The question is.. today I'm going to have to get this brassy semi orangey color out
Would it be OK if I use a blue base (the blondest beige)
With perhaps a 30 developer just for about 15 minutes..
To just lighten a bit more and get the brass out?
Or can you put a blue base after you have already used a gold base?
Will that make it green?

You will need to use a blue base color to neutralize the orange hue in your hair. You can leave the color on for 10-15 minutes to neutralize the unwanted shade.

I am a hair stylist of 28 years, you never use a developer higher than 10 on your hair that already has been previously colored, you can mix even parts of 10 and 20 developer to get 15 but do not use any thing higher, the reason why is the first part of processing is the hair is lightened and the last half is depositing color. Hair color can not lighten hair that has been previously colored, so why would you won't to use a developer that is made to lift or lighten, it just causes damage.. all you need is a level or two lighter with a 10 or 15 developer and leave it on 10-20 min... depending on how porous your ends are or just go to a professional.. you are welcomed to go to my blog msboho-whatisgoingon.blogspot.com and ask me any hair questions you want.. hope this helped.