Is there any colour blind test for the post of Tax Assistant in CBEC

My friend  has been selected for the post of TA. SSC allocated him Banglore. He is colour blind. I want to know is there any colour blindness test for this post  and whether they have right to fail candidate on the basis of colour blindness ?

no its a formality

There are excise, customs, and directorate sub-departments under CBIC. So, won't they check color blindness for TA post? Please share information here, it will be very helpful.