Planar laser induced fluorescence (PLIF) is an important combustion diagnostic technique. Development of high repetition rate PLIF diagnostic in flames is limited by the lack of high energy high repetition rate ultraviolet laser source. Limitation of two color PLIF thermometry in flames includes two parallel setup and calibration of two laser/cameras. Widely used two line OHPLIF thermometry is limited to the high temperature post flame front area. Here, we developed a practical two-color formaldehyde-PLIF thermometry scheme that can probe the low temperature pre-flame front area and directly use the high energy 3^rd harmonic output of Nd:YAG laser at 355 nm. A high repetition rate wavelength switching burst mode laser and a single camera were used to measure combustion temperature field of a laminar diffusion flame, a turbulent jet flame and a jet in hot crossflow model combustor.