You are absolutely correct about the hardness Mason - good points. Western (big leaf) maple is softer than Red leaf maple (Acer rubrum,) which is softer than Hard maple. Red maple has about the same density as Black Cherry. Red maple (we call it soft maple to differentiate from hard) is used for a multitude of things, from furniture to kitchen cabinets to hardwood flooring and molding. I have seen a lot of it in cues, but I wouldn't know if it was cored or not. If I had to make a recommendation, I would say to be safe and always core it. It is probably stable enough for a forearm, but it is not as dense and wouldn't give you the same hit as hard maple.
To answer your question about the grayish color, it is probably blue stain (sap stain). Light colored wood is especially susceptible to this phenomenon, which is caused by a fungus when the wood is dried too slowly. In summer-cut soft maple, blue stain can begin to occur in a matter of days if the lumber isn't properly taken care of. The fungus usually begins on the outside of a log or a board, so you may see it more on the end of a blank or even just on the surface. Once the wood is dry, the fungus is killed and the wood will not stain any further. Try turning the blank. It may turn right out. If it doesn't turn out, this color will definitely show up in a finished cue. Wipe some water or mineral spirits on the piece and that will give you an idea of what it will look like when finished. In my experience, most end-users don't mind some blue stain. It is a natural product and it happens. If you don't like the look, try staining the cue to hide it or dye it.
I hope this helps.
Eric
