Broken 2.3 -> 2.4 conversion for branch

[Pavel Sanda]

Hi,

when I create new branch in documt of 2.3 it has black background (my default, I use dark theme now as well).
After opening this file in 2.4 it has white background.

Looking at the 2.3 .lyx file I see that the branch contains this defintion:
\color #000000
but once I open and resave this file in 2.4 I see
\color #000000 #ffffff

It seems that the second value is used as background, so the conversion 
#000000 -> #ffffff seems wrong.

(BTW when opening new branch in fresh 2.4 file I see:
\color background background)

Anyone remembers whats going on?

Pavel