I've had these for quite a while, Cheng Hua 6-character mark in red. The genuine pieces I've found on Google don't look anything close to these, the marks and decor are mostly in cobalt, except for the doucai which this isn't. I'm guessing these are 19th century, does that sound right?
Here are some more photos
I would assume that this is sometimes in the 20th century.Foot rim picture not closeup. If the foot rim is rounded, then it is likely later. The whiteness of the glaze, unusually light colors, and the off-center mark, with a missing brush stroke in the last character, also would point to this possibility.
However, this could also be a Japanese copy of a Chinese motif, I think. I see much more Japanese porcelain with Chenghua marks than Chinese. Not sure if it is...
I would need to feel the enamel to make sure if it is fencai or a newer type of painted decoration.
Interesting, it didn't occur to me that they could be Japanese. Thanks Peter!