How light or dark they turn out depends on:
A: How much lighting you have, try adding more light objects and varying the intensity in the 'light attribute panel' I usually use about 6 lights varying from 40- 80% intensity.
B: The material you use, the reflection tab also determines how much of the ambient light is reflected. Also you can play with the specular settings. Use 'plastic' for "shinier" C4D's I like settings similar to Width 10
Height 100
Falloff -20
Inner width 30