Just because the chord is in C form does not mean that it is a C major chord either. That is just the name for the form. The chord is determined by the root note, and remember that all of these chords are moveable. If you know how to apply this lesson you will never have trouble finding a chord again.
All the forms that I have shown you so far have been for major chords. Now I will show you the small differences in chord shapes to get other chords. It is really simple when you think of the little changes that you have to make to change a chord from an A major into an A major 7. I will show you in the following charts, and I will highlight the changes in yellow. Remember: All of the forms shown below can be substituted, so if you want an A major 7 and you need an A form chord, you just have to go to the A major 7 Form below, and apply it.