Can I mix little purple with lavender to get a slightly darker lavender? Don't want purple hair.

Yes you can, it works! The vibrant purple WILL dye your hair purple IF your hair is medium to light blonde. I have used this both, to extend my salon purple dye job and to just dye my blonde hair purple when I cant get back to the salon. Hope this helps.

I have med-dark hair with some bleached chunks to carry color (currently a bright violet). Will this shampoo color my brown and the highlights??

It will definitely color your highlights but not show up as boldly on the darker parts of your hair. I've got the same sort of hair and because my roots were mostly all grown out and they were my natural brown it almost looks like a cool purple ombré. I like the look but it doesn't show up very much on darker hair.

So it only works on processed hair, so i have not colored or bleached my hair this will not work, need for party?????

No, unfortunately. It will not work. It needs porosity to deposit the color.

What are the ingredients?

qua/Water, Lauramidopropyl Betaine, Sodium Cocoamphoacetate, Polyacrylate-1 Crosspolymer, Sodium Chloride, Capryloyl/Caproyl Methyl Glucamide, Citric Acid, Fragrance, Limonene, Silicone Quaternium-20, Guar Hydroxypropyltrimonium Chloride, Propylene Glycol, Glycerin, Trisodium Ethylenediamine Disuccinate, Sodium Benzoate, Potassium Sorbate, Hexylene Glycol, Synthetic Fluorphlogopite, Titanium Dioxide (CI 77891), Hydrolyzed Pea Protein, Phytantriol, Tin Oxide, Panthenol, Tris(Tetramethylhydroxypiperidinol) Citrate, Citral, Octadecyl Di-t-butyl-4-hydroxyhydrocinnamate, Linalool, Citronellol, Basic Red 51, Basic Brown 17 (CI 12251), Basic Yellow 87, Basic Orange 31, Basic Red 76, HC Blue No. 16, Basic Violet 2