While 「塗り」 can refer to lacquer, paint seems a lot more likely here. And try to be consistent, the same word was translated as 'design' in the other three frames. While 'design' would work it's now changed to 'coloring' as this image is specifically about coloring styles. I had to look up 'aquarel' so, although it was correct, it's now changed to 'watercolor,' though that could just be me being uneducated.