Issue with bullet points!

I am using Toxic after using Blade theme and now I have blue bullet points. This is because Toxic has no bullet points of its own so the Blade bullet points remain:


So I was wondering if maybe I could add to the Toxic theme by making little green toxic waste icons like this:



Only much smaller and install it to the proper file using restorator and change it myself?

If you could help me by telling me which filetype it needs to be in (.png .bmp .ico .whatever) and where I could find the file I need to edit/the name of the file. Then I could make my own bullet point and edit it myself and I would HUGELY appreciate the help. Thank you for taking the time to read this.