How do I change the color of Strikethrough without changing the color of the text?

In some industries it is necessary to "red-line" changes that are to be made in a "controlled" document.  It would be most useful to have this function because now, I need to print the document and use a red ink pen to "red-line" the necessary changes.

Crossing something out electronically is a nonsense; period. That the facility is even made available is a questionable use of resources.

What if you're crossing out items in an electronic list but want to differentiate with color between items which are completed and items which you'd decided will not be completed...just because you haven't had a use for it doesn't deem it nonsense.

There are several good reasons to use strikethrough text. For instance - currently issueing a rolling set of actions from minutes with numbered points. Once completed these points are struck through. It would be useful to be able to use a paler line i.e. grey, so that the text is still legible despite clearly being struck through (in this our case, this would mean an item is resolved).

It makes no sense to me that a PDF file would be needed for something because Microsoft Word can't do it.

It makes no difference to me whether it makes sense to you. I was, after all, suggesting a workaround for something Word can't do - and, like I suspect you'll find to be the case with every other word-processor on the market, never has been able to do. Adobe can do it because it's just drawing static lines on a static page, not strikethrough text on a page subject to ongoing edits.

As for looking forward to "Microsoft's resolution in an update", don't hold your breath. It's not something that's likely to be added to any current version, so you'll have to wait for Word 2016's successor, at least.

Finally, as has already been said a number of times, this isn't the place to lobby for changes to Office. You can do that at: http://word.uservoice.com/. These forums are for providing solutions or, when none is available, possible workarounds. At times, too, users seems to expect Word to be able to do things, just because they want it to, regardless of the program's capabilities. Some people are quite demanding in that regard, as if it's their right to have whatever they want, so it's not surprising that the rationale for what is being asked might be questioned.