Mona, I had a lot of trouble narrowing my neutrals down, and even my colours, down. In the end, I didn't -- exactly. Instead I ended up looking at it as a kind of continuum. Your Finds show this visually -- the navy can be dark, light, or textured. And I ended up picking more than 2 neutrals. I actually use 4!! (Navy, taupe, grey, winter-white.) Five if you count black, which I use more as a colour or accent.
What I think is best is to pick at least one dark neutral (for you, navy) and one light neutral -- or a neutral that can skew light (could be grey, camel, taupe, white or cream.) And then adopt various shades of that neutral as they work.
So let's say you would like to use white. GO for it! You look sensational in all shades of white and cream, from what I have seen. And they don't have to match, as Angie shows us. My "light" neutral is technically winter white but as you know I also wear optic white and some ivory. I tend to wear white mostly in bottoms or patterns and sometimes toppers or in tops that are layered over (to show the white collar and cuffs or white shirtfront). In summer I can wear more of it.
So for our Looooong winters, your "white" might be cream....for pants you might have to go a bit textured, or look for pants that have white or off-white as PART of their makeup. For example, just look at how much wear you got from those windowpane check BR pants. They were brilliant for you, because the black bookended your hair, while the light allowed you to "lighten up" winter outfits, giving you a real boost.
Meanwhile, you can obviously wear white and cream tops and toppers all year round. White bottoms in summer are a no -brainer and easy peasy if you keep the fabrications washable.
For accent colours, again, I think of it as a continuum. So for me, it's not just "cranberry," or "fuchsia" -- it is all the colours in that approximate family. They blend well together and will look good with my key neutrals (navy, winter white, taupe) and in fact, help me adapt to each season in its turn. (Pair berry with white and you have "spring" and "summer." Pair deeper berries with navy and this is good in winter. Pair berry with taupe and you have fall.
Like Windchime, I am hoping you will keep that yellow as one of your accent colours so I can continue to enjoy it on you!
BTW, I thought of another colour I use as an accent in very small doses -- blush.