Blue is for ink -
yellow, magenta, and black!
A delight on fingers and carpeting too.

As a user of inkjet and bubblejet printers I shuddered at the prices for the consumables - those little "jewels" we buy to keep printing. Now I order"pint" bottles (that's 450ml) of ink from a family business in the US who specialize in "Odd Parts." Their web site is full of interesting mechanical and electronic bits and BULK INK for most brands of printers.

I use a Canon colour printer which has 4 x $20 separate ink tanks : C-M-Y-K
4 450ml bottles of ink cost US$99 (about C$139 with shipping) or C$34.75 ea.
1 bottle gives me 34 colour refills (13ml) which puts refill costs at about a buck!
1 bottle gives me 16 black refills (30ml) at $2.17
Rubber spheres are available to handle stopping up the tank openings after a fill. Very convenient

Clicking here can get you to the "Bulk Ink" web site in the US. It has detailed instructions for refilling many models of printer. There's another reason it costs so much less - no packaging cost. Just download the instructions for your brand of printer.