"Ugly" MetalLookAndFeel in Configurable panel

Hi,
my plugin have an ApplicationComponent and Configurable. This Configurable returns a JPanel in getComponent() method. This JPanel have some title and contains two JRadioButtons layouted by IntelliJ Layou managers (JPanel is designed by IDEA GUI designer). All works fine, except one:

These JRadioButtons have "ugly" MetalLookAndFeel. JPanel have beatiful IDEA LookAndFeel.

Have you any IDEA why it? Thank you.

-- likeapear