I am aboard the "Big Mom is Lola's Mom" train. However, one could deny it.
Some thoughts:
Do we know their official color schemes? The anime has had incorrect color schemes before, so using the anime as canon for color schemes is risky/inaccurate; we don't know they have the same color scheme.
You need to speculate Elbaf in (1) to make sense of (2), but most human beings are small; so the Elbaf stuff is just to make sense of something that seems to oppose your theory - the observation that Lola is much smaller than Big Mom. Granted, you provide a plausible explanation, but it isn't itself evidence - rather, it is a counterpoint to a possible objection to your theory (That objection being: Big Mom is way bigger than Lola).
I'm not sure what (3) means. That might be a failing on my part. Could you please phrase it differently to help me understand what you mean by (3)?
Relying on power levels talk in your theory (5) is very risky. First, because even our conversations about power levels are speculative abstractions from the manga that most people regard as meaningless or misleading; Second, because "amazing" doesn't have to refer to "power level" (but, if you construe "power level" much more broadly than in terms of raw strength, this wouldn't be an objection to your theory); most importantly, Third, "Amazing" does not necessarily mean "Yonkou." Now, you do have a really good point: They are from the New World, so their standard of "amazing" will be pretty high, but not necessarily Yonkou high. An ally of WB, for example (such as Elmy) would probably be considered "amazing." None of this is a concrete objection to (5), but you do have to be careful if you think "amazing" confirms Yonkou status - that could be bias in favor of a conclusion you already accept.
I can't help but agree with the rest of your claims though, especially (6) and (7); this would be an excellent to make Lola relevant again, something Oda pretty much promised he would do, and I can't imagine another oppurtunity as good as this one to do it. Granted, I'm not Oda, and he can be somewhat unpredictable.
All in all: I agree with you, and I think a lot of what you say legitimately counts as evidence. I think you need to be careful about some of it, though, and some of it is also to help fend off counterobjections or is bias of an already accepted conclusion - both of which are perfectly fine, and are even beneficial for a theory to have (especially the former) but properly speaking aren't evidence. I just wanted to point out that distinction, because I like distinctions, and I think it's interesting that you did a few different kinds of things here.
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@KageKageKing:
I like to think its Elmy:
[hide]http://img3.wikia.nocookie.net/__cb20101024180111/onepiece/images/thumb/2/28/Elmy_Anime_Infobox.png/500px-Elmy_Anime_Infobox.png[/hide]
That would fit most of the criteria in the first post, plus we wouldn't need to make sense of Lola's size in that case.