Which colour of the light has the longest wavelength?

Statement $(S)$: Using Huygen's eye-piece,measurements can be taken but are not correct.
Reason $(R)$: The cross wires,scale,and final image are not magnified proportionately because the image of the object is magnified by two lenses,whereas the cross-wire scale is magnified by one lens only.
Identify the correct option from the following:

Mention the colours which have the least and the most wavelength in visible light.

$A$ leaf which contains only green pigments is illuminated by a laser light of wavelength $0.6328 \,\mu m$. It would appear to be

$A$ white screen illuminated by green and red light appears to be