I got a request to stain a floor blue and after a few hours of calls and googling i still don't really know of a good way to achieve that color. I've seen a good amount of pictures of a nice deep blue but really have no idea how it was achieved

One option so far that i would obviously have to test out first is diluting blue paint to a 50-50 with mineral spirits but im VERY skeptical of that looking anything like a stained floor. The other, well not sure if it will mix together but thought of finding a blue hair dye and see if it will mix with a natural stain? Waterbase stains are my absolute last resort but i am willing to experiment with those if i must. Any ideas on how others have done this???

I have used a Glitsa Blue stain to match a carpet color. They used to also sell Canary yellow and Mint green. Now less colors are offered.
I would find the blue color that you like then thin with neutral oil to get the right consistency and opaqueness. The stain you make will be mostly neutral.

You can either tint your own stain or have someone tint for you . at a place like Woodcraft , you can buy Transtint brand dyes and mix them into almost anything to create a stain color or even tint a finish .
Another option is to use Rubio Monocoat .They offer all kinds of colors and there might be a possibility of custom colors or mixing some of their colors together to get what you want .