[Foobarz]

Ok, so I did this lab where I reacted some free halogens in aqueous solution with some halide ions, and tested to see if a reaction occurred by solvent extraction (extracting the free halogen from the aqueous solution into the mineral oil). The halide ions shouldn't be extracted into the mineral oil because ions are charge, but mineral oil is nonpolar and non charged. However, one of the post lab questions asks me why is it necessary to test the halide ions for their color in mineral oil?  My guess is that the halide ions are somewhat dissolved into the mineral oil, but this completely contradicts the "like dissolves like" idea. Can anyone help me?

[UG]

However, one of the post lab questions asks me why is it necessary to test the halide ions for their color in mineral oil? 

Are you sure they are asking this? Perhaps they mean the free halogen, after all you said yourself the purpose was "extracting the free halogen from the aqueous solution into the mineral oil"
The halogen ions are colourless, it should be the molecules (Cl₂, Br₂ etc) that are coloured

[Foobarz]

No, it said halide ions. i did test the halide ions in mineral oil, and I was surprised to find that putting the iodide anion into mineral oil would cause the oil to turn pink (is that correct or an error?)

[UG]

When you say you tested the ions in mineral oil, what do you mean. For example, iodide ion, how did you test this? Add bromine or chlorine water? What reaction(s) occurred?

[Arkcon]

No, it said halide ions. i did test the halide ions in mineral oil, and I was surprised to find that putting the iodide anion into mineral oil would cause the oil to turn pink (is that correct or an error?)

That is an error, or an anomalous result.  Foobarz:, re-read your lab description, your lab procedure, and what you did and observed.  Maybe make a table -- each ionic solution, each solution of free halogens, (consider labeling the table headers with the formula, because I suspect you're mixing them up in your O.P.,) and the visual result in the body of the table.

[Foobarz]

OK the lab procedures told us to mix an aqueous solution containing the halide ion (eg, sodium chloride, sodium bromide, potassium iodide) with the mineral oil, then see if there was any color change. Oddly enough, there was a color change for KI (I^-). But if mineral oil is nonpolar, shouldn't there have been no color change since the ions wouldn't be extracted into the oil? So my question is why they ask me, "Why was it necessary to test the halide ions for their color in mineral oil?" (This question is copied verbatim, it has to be the halide ions.)

[Arkcon]

Well, there's a good reason why the lab practical would ask you to try to analyze something, before and after a reaction.  Can you think of a reason why?  Not just for this example, but for other labs you've done.

Also, you expected a certain visual result.  You've made it clear, you didn't get the result you expected.  That doesn't make it impossible for you to report what you've seen, and it doesn't invalidate the usual reason for a "before and after" visual check.