Upon using a Young$$s double slit apparatus, the following measurements were taken.

$8=1\mathrm{.}120($for $8$ th node$)$

L $=3\mathrm{.}02$m

m $5$ m $1=2\mathrm{.}95$cm

d $=0\mathrm{.}00025$m

Using this data determine the wavelength of light being used in the apparatus. What colour is the light?