Citadel Teclis Blue Layer Paint is designed to be multi-layered. This blue color is slightly transparent, so you can use it to build your color over several layers until you're happy with it. Now the paint does require a bit of practice to use, but the results are well worth it.
The layer paints are best used as a 2-step highlight, so two paints for each color but this is a guideline. For example, Teclis Blue can be combined with Lothern Blue. You start with the darker of the two and apply it to the surfaces that you want to eventually provide this blue color.
Because the paint is a bit transparent, you will continue to see the base color a bit, but by using Teclis Blue together with Lothern Blue, you can use that transparency to apply the layers. If you apply the lightest color after the darkest color in maybe 1 or two layers, the last highlight of the lightest color will ensure that you have a great result.
The color of Citadel Teclis Blue (22-17) is similar to: The Army Painter Electric Blue (WP1113); Old Citadel Lightning Bolt Blue; Vallejo Game Color Electric Blue (72023); Vallejo Model Color Sky Blue (70961); Instar Bright Blue; Rackham Sacred Blue 2 (8); Reaper Master Sky Blue 2 (9018); Coat D'arms High Elf Blue (117).