Materials confusion

Sorry I seem to be filling the forum at the moment, I'm a little confused ref. materials workflow. I have duplicated a material in the 'swatches' window renamed it 'logo', changed it a little and dragged it onto my object.

I then click on the object, and the material appears in the 'Material Docks', if I d/click that material and another version of that 'logo' material appears (in the 'Material Docks') with a .2 appended, (I clicked around a bit and have another ... logo.4) so what material IS applied to the object ? logo or logo.2 or logo.4 and do I need to get logo .2 or .4 into the material editor window to tweak the colour ... and what are these extra swatches logo.2 or logo.4 confused ... advice please.

Roger