Most of the beamer element colors in a beamer template are dependent on other colors. Look for example at the default color theme. Nearly all the element's colors are dependent on these four "base colors".
Also there are the four palette colors (again here the definition in the default color theme), which are kind of important.
So if you design your own color theme you should keep that in mind. Using these "base colors" make it much easier and faster to define your own color theme.
In short: if you use the default color theme, changing the beamer color
structure should already change a lot.