customizing header-line face

[Ralf Mattes]

Hello list,

is there any convenient way to customize the face used for header-lines
buffer-local? I'm trying to get header lines with different backgrund
color for different buffers (on the same frame).
I discovered the 'header-line face but since faces seem to dwell in the
plist of a symbol making 'header-line buffer-local doesn't work.
Any ideas?

 tia Ralf Mattes