In Jainism, there is no strict rule regarding the color of cloth to be worn during jaap (recitation of mantras or prayers), especially for lay followers (śrāvaks and śrāvikās). However, the following guidelines are commonly observed based on Jain principles and traditions:

1. Simple and Clean Attire: The most important aspect is that the clothes should be clean, simple, and modest, reflecting humility and purity.

1. White Clothing: Traditionally, white is considered the most suitable color, as it symbolizes purity, peace, and non-violence (ahimsa). Many Jains, especially while performing religious activities such as jaap, puja, or attending temples, prefer to wear plain white clothes.

1. Avoid Bright or Ornate Clothes: It is recommended to avoid bright, flashy, or ornate clothing, as these can distract the mind and go against the principle of aparigraha (non-possessiveness).

1. Monks and Nuns: Jain monks and nuns (sādhus and sādhvīs) follow stricter codes, usually wearing unstitched or simple white cloth (in Śvetāmbara tradition) or going without clothes (in Digambara tradition).

In summary, for jaap, it is best to wear simple, clean, preferably white clothes, focusing on internal purity and devotion.