Alright let's say I have a circle or any closed shape for that matter. Maybe a jester's hat. One line, one path, one object. I want the stroke to be black and the fill to be exactly half blue and half pink. I do not want to add another line. I want the blue to touch with the pink in a perfect vertical line all the way down the precise center of the object. How is this done?

the easy way is With a linear gradient:

http://tavmjong.free.fr/INKSCAPE/MANUAL ... -Gradients

Yes that was my first thought but I cant figure out how to reduce the blend of the colors. I want solid pink and then directly to solid blue.

Then you need to add more steps.
One step for the two ends, two for the middle -exact same position-, and set the two colour values for the four steps.

On a side note, gradients render aliased -the break between the colours may not be crystal sharp in small resolution-.

Another option is open paths married at the middle, particularly if the object is symmetrical.


Two clones with differing fill. Original has unset color.

(Download to examine the file in Inkscape and modify the original object.)