Why is it an offense to wear red or blue clothing in the Kṛṣṇa temple?

Śīlavatī: I understand that it is an offense to wear red or blue in the Kṛṣṇa temple. Why is this true?

Prabhupāda: What is that?

Devotee: She says that it is an offense to wear red or blue in the temple.

Prabhupāda: Blue?

Devotee: Red or blue. She wants to know why this is.

Prabhupāda: I do not follow.

Madhudviṣa: Why is it an offense to wear red or blue clothing in the Kṛṣṇa temple? That's what she thinks.

Prabhupāda: Oh. (laughs) Because it is red and blue. Is that all right?

Śīlavatī: Because the temple red and blue?

Prabhupāda: You see, you have to accept the Vedic injunction as it is. There is some meaning which may not be explained immediately, but because it is so enjoined, we have to accept it. Just like the conchshell. The conchshell is the bone of an animal. Now in the Vedas it is said that if you touch the bone of an animal or human being, you have to take bath immediately to purify yourself.
Now, this conchshell is also a bone of an animal. Now, it is kept in the Deities' room. Now, if you say, “The bone of an animal is impure. How it is that it is kept in the Deities' room?" So actually it is being done. Why it is being done? Because it is injunction of the Vedas. Similarly, all such injunctions we have to accept, but there is meaning. There is meaning, and that may not be understood immediately. That doesn't matter. So if, instead of red garment, if you take this saffron, what is harm to you? So you should accept the injunction.”

-Bhagavad-gītā 2.27-38,

Los Angeles, December 11, 1968