Glenn and Jim, it's clear from your photos that those walnut pieces have faded, yet mine have not. The clock I showed pictures of hangs on my living room wall and gets daily indirect sunlight from both left and right, at least as much as we get in WNY. Bill's question about whether or not the lightening effect is regional is interesting. I have no clue, but it looks like not all black walnut behaves the same. The difference isn't necessarily kiln dried vs. air dried, as you used AD lumber, Jim, for your projects; I suspect Glenn used KD. The clock I showed used air dried wood, then kiln dried at 110F without steam. The bowl was turned green and then air dried.
John