NOX emissions and flame characteristics in gas turbine burners are a current issue. Different combustion methods are tested for the solution of NOX emissions. One of these methods is oxy-colorless distributed combustion. In this method, CO2 is used as a diluent instead of N2 gas in the air. In this way, nitrogen does not enter the combustion chamber and theoretically NOX emissions are planned to be zero. In this study, a premixed and swirl assisted gas turbine combustion chamber used experimentally was verified numerically. Analyzes were carried out by keeping 3 kW thermal power, 1 swirl ratio and 0.7 equivalence ratios constant. The oxy-colorless distributed combustion method was applied to the pure methane flame at different O2/CO2 ratios. Analyzes were carried out with the O2 ratio of 26%, 21%, 19%, 17% and 15% by volume. The results showed that the colorless distributed combustion conditions were achieved as the CO2 ratio increased. Thanks to the oxy-colorless distributed combustion method, almost zero NOX emissions have been achieved. In addition, as the O2 ratio in the oxidizer mixture decreased, a significant decrease in the flame temperature was detected. Thanks to this study, the effect of oxy-colorless distributed combustion conditions in a premixed and swirl supported combustion chamber was investigated.