Fyi I have both kits that the OP has listed. One installed on the contour and one installed on the mazda. A few weeks ago when the weather was dry I pulled both cars out and parked them side by side and the difference is incredible. The 55w 4500k (4300k) bulbs are so much brighter and are noticably whiter. As far as the 4300k being yellow with the 55w ballasts, thats not true at all.
I will try to get a picture when it stops raining but I will say that the contour looks dim and blue compared to the protege and I am half thinking about getting a new 55w kit for the contour.