For the interference pattern to be formed on the screen, the sources should be coherent and emits lights of same frequency and wavelength.
In a Young's double-slit experiment, when one of the holes is covered by a red filter and another by a blue filter. In this case due to filtration only red and blue lights are present. In YDSE monochromatic light is used for the formation of fringes on the screen. Hence, in this case there shall be no interference fringes.