I download 'Color Button' plugin and its dependencies 'Floating Panel', 'Panel Button', ''Panel, 'Button' plugins.
unzip and upload them to the /site/modules/InputfieldCKEditor/plugins directory.
go to Setup -> Fields -> myfield -> Input, scroll down to the 'Plugins' section and check the box for these 5 plugins. Save.
but the Color Buttons are not automatically added to the toolbar.