This is seen on current pit build for 6u10 b07, on all Oses, with Nimbus L&F.
Run Swingset2, tab to the ColorChooserDemo and Tab to to any of the HSB or RGB tabs in the Colorchooser. 
Select text in the JSpinner's textField. 
Observed behavior: Color of the Selected Text remains Black and so the text is not very clearly visible in the textfield. 
Expected behavior: Color of the Selected Text should change to White.
Please see the attached image for reference.