I, like 5% of the male population, am slightly red-green colorblind. The Breadboard view in Fritzing uses a subtle red or green color to indicate when a component is properly connected to a hole in the breadboard. This particular form of colorblindness makes it very difficult to distinguish the red indicator from the green indicator.

I only noticed that some of my components were slightly misplaced because they were not connected in the Schematic view. A close look revealed the colored indicator feature. Prior to this I had not realized that it provided an indicator.

Please consider adding an option to adjust the colors used for indicators such as this, or select a stye of visual indicator that does not depend only on color. For example, an unconnected pin indicator that blinks for half a second after a component has been dropped and on mouse hover.

In the meantime, other users who have similar colorblindness issues (often they don't even know who they are) can use the free Visolve Deflector application to help make these indicators more obvious. It's a very useful application, in fact, I just discovered another unconnected wire!