There is no legal rule, but in Indian government offices, particularly in the legal judiciary, the following rule is followed: only certain authorities are allowed to sign in red or green inks. For example, gazetted officers can only sign in green ink. So, at home, you can sign in any ink, but as mentioned by one member in a school application form, you have to use only blue or black ink.
While there is no explicit legal rule, the Manual of Office Procedure does make some references to the use of different colored inks by officers at different levels. Generally, blue and black are used at the lowest level, green in the middle level, and red at the highest level. However, it is important to note that regardless of the color used by different levels, officials sign with either blue or green ink, preferably. The extract states that record-creating agencies should use fountain pen inks and ballpoint pen inks of a permanent nature as prescribed by the Bureau of Indian Standards. The guidelines specify colors for fountain pen inks (blue/black) and ballpoint pen inks (blue, black, red, or green).
Paragraph 68, sub-paragraph 5 of the Manual of Office Procedures now states that initial drafting will be done in black or blue ink, with modifications at subsequent levels in green or red ink to distinguish corrections made. According to Paragraph 32(9) of the manual, only officers of Joint Secretary level and above may use red or green ink, and that too only in rare cases. However, Paragraph 68(5) does not restrict the use of these colors to any specific rank.
The significance of different color inks on legal documents can vary. In law, red ink in a signature can indicate that the author is signing as a living man or woman. Black and blue ink may signify signing in the capacity of a corporate entity, such as state statuses or offices. The choice of ink color can convey specific meanings and implications on legal documents.
While it is not entirely clear, different color inks can have specific legal implications based on traditions or organizational practices. It is essential to understand the potential significance of ink color choices in different contexts.