If you can get it, Ash wood is a cheaper alternative to oak. It is practically identical in appearance to white oak (minus the axial grain rays common in mission style furniture) when stained and it is very hard - that's why it is used for baseball bats. I love alder and have it all over my house, but I also hate oak (IMO overused, bland, little grain character) so you won't see that combination of those two with me. However for your case, IMO they are way to different to try to stain them to look similar. I've said this many times on this forum. Think of wood like fabric. It comes in many different weaves and textures (aka grains) and you can always choose to color different looking pieces the same. The question is whether you want different looking fabrics w/ (nearly) identical colors in your design. My answer is no (I'd choose to highlight the contrasts rather than poorly disguise them), but your answer is your own and it's always the right one for you.

Ive refinished hardwood floors for over 10 years. And while both maple and white oak have differences its mostly down to color that seperates them. Maple is "harder" based off the Janka rating system used by industry. But dont be fool all wood will dent if something is dropped. But back to color. Yes maple is lighter in natural tone but doesnt accept staining well. It can be done and look good but not as evenly as oak does. Oak is of course darker and also has thicker grains then maple. If you are going natural with the finish i personally like white oak over maple. Maple tends to become too orange as the floor ambers over time.

Same here. I extended my carpeted area to hardwood flooring. My contractor put new red oak in place of white oak and the stain stick out like a soar thumb. I don't know what to do. We haven't poly'ed yet. Any suggestions please?

@Joe Macker. I added protective film to my windows to block UV rays from causing damage. The advantage is that this protects everything in my room. I had damage to my furniture - both cloth and wood from the light streaming in. I have an Eastern exposure. You can't tell that there is any kind of protective film on the windows as mine are not tinted - or tinted so slightly that there is almost no difference but they are rated for close to 99% blocking of the UV rays.