Even though you've said you want us to choose according to ease of readability, I still have to wonder where it will usually be seen -- in print, or on the internet, or at least computer screen. And if this is very important, you may want to take color blindness into account....unless you don't plan to use colors, other than black and white. Although I have the impression that certain types of colorblindness affect black and/or white. But I'm certainly no expert.
The black on white (Shavian) I think is more easy to read, because the letters have more space between them. But put the same space between the English alphabet letters (on the left) and I would have a hard time choosing.
I still think a different font for the traditional alphabet (white on black) would help a lot. Or at least italics. Because in the black on white (Shavian) the alphabet letters are quite different from the other text ("Shavian alphabet:" and "48 letters. 1 letter = 1 sound"), and it makes them stand out better. With the white on black, the traditional alphabet uses the same font as all the other text, and that helps to make it harder to read.
But the more of this stuff you fix, the harder it will be to make a decision about which is easier to read. What I really don't understand, is why it matters whether it's black on white or white on black? If you need us to choose between black on white or white on black, you need to give us the same image both ways. Or am I stil missing the point?
Off topic:
Not that it matters to this discussion, but I don't quite understand this Shavian pronunciation thing. What about people who speak British English, or Australian English, or S. African English? Or what about accents. In the south and southeastern US, "dog" is often pronounced "dawg". How can the Shavian system handle accents? I actually was born and had all my schooling in that part of the US. I've lost the accent now. But I had a hard time learning how to read by phonetics, which was popular then. Especially the short e sounded as much like a short a, short u and short i, and I found then indistinguishable audibly (?). I learned to read by recognizing patterns of consonant sounds, because the short vowels sounds befuddled me. (I could win a bundle of money on Wheel of Fortune because I would never need to "buy a vowel", lol!) In other words the short vowels sounded the same to me because even within that region, there are many variations to the southern accent. Louisiana's accent is very different from Alabama's, which is very different from Georgia's, which is very different, etc., etc. Anyway, there are many variations, and that's just the southern accent. There's also New York, midwestern, Canadian, the infamous Baaaastan (Boston, Mass), etc., etc., which I'm sure all have several to many variations!
Then we have foreign language accents, French, Spanish, etc. What about words that are pronounced differently by the speaker's tradition -- "root" - some say "rooooot", others pronounce it like "foot" Same with "hoop" Wouldn't that mean there would be 2 spellings for the same word, depending on how the speaker pronounces it? Same with "dog" and "dawg" and we're back to accents again

What about Black's accents (African Americans)?
So what I mean, is how can 48 letters cover all those sounds, and only have one sound per letter? I guess on first blush, I probably won't expect to be a fan of this, lol

But I'll read the Wiki article, and maybe I'll understand better
