There is no any issue with coloured or printed admit card only matters that it should be clear in Photograph. You can also carry your clear two photograph with you for safe & side. for further information about the exam you can go through with the given below link.
CLAT 2018
Good Luck!
Goo
Admit Card | Application | Eligibility | Exam Pattern | Preparation Tips | Question Paper | Exam Centre | Accepting Colleges
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile