@ractorIII If it's a mixing hot end then think of it as single digit percentages divide by 100. So E0.01:0.99 works. As does E0.15:0:15:0.70. But I'm pretty sure that you can't go to more than 2 decimal places (at least you never could unless something has changed recently).
If you use multiple extruders in a push - pull arrangement then the mixing ratio would be 1:00:1.00
Edit. I've just noticed you signature and realise that you might not have a hot end as such. In which case substitute mixing hot end with "multiple inputs, single output".