Probability charts for each color are being added to the FAQ. These should give you a rough idea of the most likely colors that certain pairings will produce. It's not specific to individual horses so just be aware that there are several variations of genes for many colors and the charts are showing the most common possibles.

Note: The chart does not take rare colors into consideration for the breed either. So if a color is rare for your breed the chances are also reduced of getting it and you might want to look at the most likely non-rare color that comes up on the chart as the likely outcome.