Summary form only given. We have developed a range of polymers based on phenyl-PPVs which are now being commercially exploited in the first polymer LED applications. These materials have been developed systematically to meet the demanding device requirements (e.g. high efficiency and lifetime) and industrial applicability (e.g. processibility, reproducibility and reliability of supply). A wide range of PPVs with different properties (color, efficiency) is manufactured at the Covion production site and is available as a "ready to use" formulated product on a commercial scale. We report on progress in the development of red, green and blue materials. The requirements for the different colors vary depending on band gap and therefore the challenges for each color are different. The experience gained in understanding important structure-property relationships in phenyl-PPVs as well as that with high performance small molecule materials (spiro materials) has been employed for the development of these polymers.