Brassy Blonde About To Recolor. Please Help!

Sorry we haven't been answering you, its because your questions are tough!  I'll explain why.  Your hair in the second pic looks all one color, light brown.  Your hair in the first pic looks medium brown with a very slight orangish tone (which is what I interpret you to mean when you are calling it brassy).  I don't see any highlights or purple.  Pics do help, but they are not always accurate because cameras can pick up different colors based on the light your hair is under, so it could be that they don't accurately represent the hair you see in the mirror, and that may be some of the confusion.

I can explain some of what happened - if you had blond hair when you were younger, a box of blond dye was probably all you needed to get lighter blonde.  In the late teens or early 20s, many blondes' hair turns darker, so what worked before won't do it anymore.  That's where the brassiness, or orange tone is coming from, you aren't getting it lifted past the orange stage anymore with the same product.  Also, violet counters yellow, so if your brassiness really is orange and not yellow, it won't do anything to help orange. (Blue counters orange).

I don't think 30 volume developer is going to lift it enough for you anymore, no matter what dye shade you choose to go with it (this again is based on looking at your picture).  You will either need a high lift violet based dye with 40 volume developer; or hair bleach then violet toner over it.  If you don't want it very blonde, you will have to test strand these to get the timing right, because the bleach will go blonde fast, and also test strands are necessary to make sure it works and doesn't give you more orange.  Analyze your test strands under different kinds of light too, sun will make them look whiter, but fluorescent lights can make lightened blonde hair look crayon yellow - so make sure you will like what you do before you do your whole head).  Once all your hair is dark yellow, that violet shampoo should work better, but I warn you that brassiness will be hard to avoid, hair lifts through orange to yellow, and yellow is brassy.  Dark ash blonde can be challenging to acheive.  It does usually require some upkeep to keep it ashy.  Toner is not permanent, so if you go that route, you'd need to redo it occasionally. 

If you decide after reading this that you don't want dark blonde, you can get rid of the orange tone by using a light brown or dark blonde dye with a green or blue base and only 10 or 20 volume developer (to avoid more lift - green bases counter red in the hair, blue counters orange) - but be sure you test strand that too.  If your hair is really blonder than in your pics, your hair could come out grayish or greenish using those --- always test strand.