Most products of that type, in my experience, are more like a form of paint than ink. That is, they're a latex based pigment carried in a water based solution, rather than a dye solution. Most will come off with soap and water and scrubbing, especially before they're fully dry. This obviously works best with durable clothing items; if you spilled this on a silk suit, take it to a professional, because you're more likely to completely destroy it than clean it, but if it's blue jeans, khaki, or similar sturdy stuff, get some soap, warm water, and a brush and scrub away.