getting my hair to take directions silver dye

Using a box blonde is still bleaching. It's the same process, it just also adds some colour at the same time, along with silicones at the same time normally.

So you want silver? I'd say from that photo your hair isn't light enough for a light silver. Please don't attempt to use another peroxide product for at least a month (including blonde hair dye, or a toner). You've already used two in one go with isn't good. If you want  a darker silver then you need something like Pravana silver.

Also, what is your hair history, what did you have before using the blonde dye? We can help advise what the next step is when we know what you've done previously.

Thanks for the response. I'll definitely leave it then and give it a break, and try to lighten considerably before trying the directions silver again at a later date.

So far as my hair history, I have dark blonde hair which has been lightened to a mid-to-light blonde.
I had a bleach disaster about two or three months back when trying to bleach blue out of my hair (idiot mistake) and it went a patchy blonde & green. I faded that out (cleansing shampoos, vit c treatments etc.) and then had it colour corrected at a hairdressers, where they managed to take it back to a mid-blonde.
A few weeks ago, I had the regrowth done at the hairdressers again, but they toned it very golden/yellow so after a week I used the Schwarzkoft Live Colour Silver Toner, and then attempted the directions silver, which didn't take.
My hair is remarkably healthy for everything it's gone through too - counting my blessings.

Directions Silver works best on lightest blonde hair. For the best result on darker hair, wash with a clarifying shampoo, no conditioner. Then apply, cover with a shower cap etc and apply heat from a hairdryer. Cover to keep the heat in and leave on for 4 hours or more. Rinse with cool water only.
If it is still too light try diluting Neon Blue with white conditioner until it is just a smidge darker than the silver toner. Use the same method described above to apply, but try on a strand test first.

Thanks, that helps a lot! My hair is fairly light, not white but light blonde (the pic i took was inside and dark so not as good at reflecting that) so I'll give your method a try. Much appreciated!!

Directions Silver works best on lightest blonde hair. For the best result on darker hair, wash with a clarifying shampoo, no conditioner. Then apply, cover with a shower cap etc and apply heat from a hairdryer. Cover to keep the heat in and leave on for 4 hours or more. Rinse with cool water only.
If it is still too light try diluting Neon Blue with white conditioner until it is just a smidge darker than the silver toner. Use the same method described above to apply, but try on a strand test first.