The odd captions for inputing pure black/white picture to the BLIP model

[FaxinZ]

Hi!

I am playing around with the BLIP model, and it works well for most images! However, the output is getting weird if I input the pure black/white images into the model (please see below):

Are these the default settings for the BLIP model? Or anything I can do to modify the output? Thank you in advance!