The aim of our study is to develop an intelligent control system for mixing color ratios using LED lights in a greenhouse environment. To this end, different components of an experimental testbed is presented for achieving the desired light requirements for plant growth in a greenhouse environment. The proposed testbed provides a easy-to-use plant growth system with IoT-enabled control and monitoring features. To testify the features mentioned above, a feedback lighting control method to achieve a desired photosynthetic photon flux density (PPFD) set point is implemented. A two-week experiment was conducted on microgreen kale which was planted in the testbed and harvested at the end of the experiment. The experimental results has shown that the tested microgreen kale grew with a healthy condition in the proposed testbed and lighting environment.