Hello,
Since the upgrade to the last version of Zenphoto, some of the image thumbnails are in black and white and some in color even if the black and white option in my theme (ZpArdoise) is checked. I tried with another theme and it's exactly the same. Does anybody know how to fix this?

Maybe there are cached versions of the color ones? Try clearing the cache. Also possible is that the theme does not "tell" Zenphoto it is making a thumbnail, so if the option is set for thumbnails it might not be applied if Zenphoto thinks it is rendering an image page image.

Thank you for your quick reply. After clearing the cache, all my thumbnails are now in color, I tried with different themes and it stays in color. So I think you're right but I still don't know what to do to have my thumbnails in black and white...

Options > Theme > Grayscale conversion

I've already done that, the box is checked but it still doesn't work... It was working with the 1.4.1 version but not with the 1.4.2. Am I the only one encountering this issue?

Did you clear the image cache? There are no new images in b/w created otherwise.

Yes I cleared the cache many many times and thumbnails are still in color. Never mind I will try to get used to it

Seems this is a bug. Grayscaling is only applied if the image is cropped. This will be fixed in tonight's nighly build.

Thank you !