I think .properties files under
  src/share/classes/com/sun/swing/internal/plaf/metal/resources
and
  src/share/classes/com/sun/swing/internal/plaf/basic/resources
should be localized more carefully. In those files, only Text and Label
have been translated. Because Mnemonic and DisplayedMnemonicIndex have
been ignored and unchanged on localization, mnemonics of some Swing components
look wrong for some locales.

For example,
  ColorChooser.swatchesNameText=\u30b5\u30f3\u30d7\u30eb (S)
  ColorChooser.swatchesMnemonic=83
  ColorChooser.swatchesDisplayedMnemonicIndex=6
might be better than the following current entries:
  ColorChooser.swatchesNameText=\u30b5\u30f3\u30d7\u30eb
  ColorChooser.swatchesMnemonic=83
  ColorChooser.swatchesDisplayedMnemonicIndex=0
(basic_ja.properties)

  ColorChooser.swatchesNameText=Muster
  ColorChooser.swatchesMnemonic=77
  ColorChooser.swatchesDisplayedMnemonicIndex=0
or
  ColorChooser.swatchesNameText=Muster
  ColorChooser.swatchesMnemonic=83
  ColorChooser.swatchesDisplayedMnemonicIndex=2
might be better than current entries as well:
  ColorChooser.swatchesNameText=Muster
  ColorChooser.swatchesMnemonic=83
  ColorChooser.swatchesDisplayedMnemonicIndex=0
(basic_de.properties)

For the above two examples, at the moment, the first character
(\u30b5 in ja locale, 'M' in de locale) is underlined as if the character
is a mnemonic. Of course, these fake mnemonics don't work. 'S' works for
each case.

I think all localized .properties files under these directory should
be reviewed and expected behavior for each (localized) mnemonic should
be verified with testing.