As eligibility criteria of the Indian Engineering service examination has not mentioned that the candidate having colour blindness are eligible or not. So in think you can apply for Indian Engineering service examination

Indian Engineering Services examination is organized by union public service commission

IES Exam Eligibility:

Educational Qualification:
-You should have passed undergraduate degree in Engineering or equivalent from a well recognized university
-The M.Sc degree or its equivalent with Wireless Communication, Electronics, Radio Physics or Radio Engineering as a special subject also acceptable for certain posts.

Nationality:
-Must be an Indian Citizen, subject to Nepal and Bhutan

Age Limits:
Must have attained the age of 21 years and must not have attained the age of 30 years