I think this coloring page of the Princess Cadance and Shining Armor is absolutely beautiful and will make a lovely addition to any coloring book. To begin, I would color Cadence's dress a pristine white and her hair a gentle golden blonde. For her bouquet of flowers, I would use vibrant shades such as light pink, coral, and lilac. For Shining Armor's tuxedo, I would use black as the base color, and then use a bolder red for his bow tie and white for his shirt. The sky and any other elements of the background should be filled in with a few shades of blue for a dramatic and peaceful effect. The two characters should also be shaded to give them depth and life and I would add a sparkling white to emphasize Cadence's tiara and jewelry. Finally, I would add a few touches of warm yellow to give the image a bit of sparkle and joy. I'm sure that when all is said and done, the coloring page will be a beautiful work of art.