This study was conducted to determine the effects of LED lights in different colours (Daylight LED, Blue LED, Red LED and Blue LED + Red LED (50%+50%)) on emerging rates of R. luteum seeds and seedling growth). The LED lights were applied to the seeds grown on the acidic peat in foam cups superficially in the form of 16:8 hours (light:dark). The results showed that the emerging rates in seeds subjected to Daylight, Red LED, Red + Blue LED and Blue LED light were determined as 61%, 45.66%, 43%, and 35%, respectively. The effect of different light colors on plant height was significant (p<0.01). Red + Blue LED, Red LED, Blue LED and Daylight LED subjected plants' heights were determined as 10.342 cm, 10.262 cm, 75.06 cm, 7.139 cm, respectively. Diameters of seedlings were determined in Daylight, Blue LED, Red LED, Red + Blue LED subjected seedlings as 0.147 mm, 0.104 mm, 0.085 mm, 0.077 mm, respectively (p<0.01). The number of leaves were determined as 3.547, 2.000, 1.550, 1.302 in daylight, blue LED, red + blue LED and red LED subjected plants, respectively (p<0.01). To conclude, the best emerging rate and seedling growth were obtained from daylight treatment. Although the higher seedlings were obtained from Red+Blue LED and Red LED treatments, these seedlings were found as weak with thinner stem and less leaves.