Based on this google search you might need to use another brand..... https://www.google.com.au/search?q=b...HWqvD68QsAQINg Mister Minute kiosks in shopping centres often have colour change bottles mainly used on ladies shoes plus they also have a big range of colours and reckon they would have blue in traditional 'Nugget' style too.

Hope you have a long white lab coat handy if going down the mad scientist path. Things could get messy.