For some reason, the Color Picker dialog is the default way of setting a color in several color induced effects: Drop Shadow, Inner and Outer Glow.

Most of times these effects are used, we need to toggle between black and white. These are more or less OK to pick quickly, if we change the mode of the dialog to Color Swatches.

But each time this dialog is called when editing a color for the effect, the dialog open in the first mode, Color Models.
And to set black or white in this mode we need to click the spectrum field and drag the point into a corner. You get accustomed to this, and realize you can move the mouse beyond the the dialog, making the precision gesture 'infinite' — and this is what MANY users do, if you watch tutorials or timelapses.

But this is bullshit. We just need black and white, without fiddling with the spectrum. More of it, in a CMYK document setting black like this would make it rich black, and not K100 — which one would have to set manually, by typing it.

Since there is a request about adding Recent Colors, perhaps into Swatches or Color (http://illustrator.uservoice.com/forums/333657/suggestions/44772598), perhaps we should be given an option to see these in Color Picker as well (a lot of users prefer it to Color+Swatches panels). In this case, just make Black and White always there, as a fixed choices.

Another solution would be just to display the same 'Color UI' used for any other place in Ai, the Swatches + Color Mixer (minus Gradient and Generative Pattern, obviously).