Young's double slit experiment is carried out by using green, red...

The fringe width in Young's double slit experiment is given by $W = \dfrac{\lambda D}{d}$.

For a given experimental setup, $D$ and $d$ are constant, so $W \propto \lambda$.

The wavelengths of red, green, and blue light follow the order $\lambda_R > \lambda_G > \lambda_B$.

Therefore, the corresponding fringe widths will be in the order $W_R > W_G > W_B$.

Answer: $W_R > W_G > W_B$