Imbuing your pieces with energetic color has a lot to do with contrast. The colors do not necessarily have to be bold and bright, although bright colors have an inherent energy of their own, but rather they need to be a mix of warm and cool, bright and muted, or any combination of color characteristics that make the colors vie for dominance, visually.
The colors in this brooch by Pavla Cepelikova have a fun combination of bright and muted as well as cool and warm colors. By themselves, they would give this piece a moderate amount of energy. Applying the colors in stripes adds to the intensity of energy as variation in color alternates up and down those striped strips.
Her use of lines also adds a tremendous amount of energy. Not unlike the way they use lines in animation to denote when something is moving, she has added energetic lines around the petals as if they are shaking on the surface of the brooch. The combination of energetic color and lines makes for a very lively piece.