make JBColor.namedColor use notNull with factory method
make JBColor.namedColor use notNull with factory method

GitOrigin-RevId: e26f2c9e3f885bda0584f147065657930f59ccc5
allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community