Question

Give me the hint to learn rainbow colours?

Answer 1

VIBGYOR or ROYGBIV 
u can learn it easily if u learn this sentence. 
that is 

R-Richard...red 
O-of...........orange 
Y-york........yellow 
G-gains......green 
B-battle......blue 
I-in..............indigo 
V-vain.........violet 

.....Richard of york gains battle in vain....

Answer 2

V-violet
I-indigo
B-blue
G-green
Y-yellow
O-orange
R-red
"VIBGYOR" is the way to remember rainbow colors