Hello again, my opinion is that on the screen it realy looks more black then the gray! My advice is for a colors without raster in case you gonna make hats, cups, t-shirts and stuff like pens or lighters ... Even that there is so many printing technologies for the raster stamps on any kind of rounded and relief surfaces, you gonna need a white basic surface for the raster images ... But on the end, there is nothing impossible in printing theese days, so here is some new ideas
... I think that gray color correspond with every color but it is only me, I made also a few combinations with blue!