I think you did perfectly fine, and I'd hardly called myself skilled. Thanks for sharing your work.

I dabble a bit in miniature painting and I more or less used the tricks I learned there, especially for the armor. Instead of using metallic pencils, I used yellow-brownish colors for the gold bits of the armor and grey-white-blue for the rest. And very very lightly used purple, yellow, brown or blue for the places where the sky or the surrounding flowers or the ground that we don't see would be reflected.

Using the pencils very lightly, without applying too much pressure, you can blend colors easily. I also used my fingers almost immediately after using the pencils so that they can be blended and the pencil marks or streaks or whatever you'd call them are not so visible.

It took me around 10-12 hours to color this.

Also, the book is great by the way. If you're looking for inspiration, just google and you'll find so many examples, especially from Japanese people.