Hello Dear,
See Carefully...
IN My Knowledge,
1. Earlier the Use of Pencil and colored pens were not allowed.
2. Now, you can use pencil . In this regard you may see guideline which are issued firstly along with examination form and second time when you get Admit card for exams.
3. So far as colored pens etc. are concerned ,these are still Disallowed.
4. As rightly said by my frnd, Rajan, you can underline instead to use colored pen to give good impression.
5. Other important thing:
Try to make paragraphs by making one line blank between each para. Ideally no para should have more than 6 or 7 lines.
Just try to wright two pages with 6/7 lines para as mentioned above. Now see its attraction.
What about this reply. One blank line, Numbered para gives easy writing , Viewing and most importantly GOOD MARKS.
Your Frnd,
S/o Sh. Bakshi Ram Verma