In the upper right pane of the render editor, there is a lights hierarchy. Expand it fully. There is an ambient light and a directional light. Lower the values in the ambient and/or directional RGB to darken the light. You can also change the color of the light by making either the R, G, or B more or less. (Red, Green, and Blue)
Easter Egg Icons
These icons are for celebrating Easter season with! Why make real eggs when you could have ICONS that look egg-actly like them (see what I did there, huh...huh)! PUN INTENDED!
I appologize for the low-quality...I had a problem with Unicorn 3D. Any of you out there know how to make the light not as bright when you make a rendered image in Unicorn 3D?