Supoose some non-slaughtered-animal or non-kosher-species ingredient gets mixed accidentally into a larger food. From what I understand, if the non-kosher ingredient is not thought to add flavor to the mix, is not more than 1/61 of its volume, and cannot be picked out of it, then one can usually eat the mix. (There are exceptions; e.g., non-kosher food stabilizers.) And the same is true of ingredients that are forbidden due to (most) other prohibitions, though the proportion 1/61 may vary some.
Suppose the non-kosher ingredient cannot be picked out (it's mixed in thoroughly) but is clearly visible. For example, wine in water, sufficient to color the water but not to add any taste. Or (I frankly doubt that that's possible, actually, so here's another example,) non-kosher food coloring. Does the visibility remove the permissibility (even if only by late fiat)?
(Note that this question is about an ingredient that made its way into a mix accidentally. One cannot put even a tiny amount of non-kosher food into a mix on purpose and doing so can make the mix non-kosher even if it would be kosher had the non-kosher ingredient been introduced accidentally. As always, consult your rabbi with any practical questions.)
