According to Jainism, the Tirthankaras are extraordinary souls who have attained perfect knowledge (Kevala Jnana) and have transcended all karmic bonds. Jain scriptures mention that Tirthankaras are born with exceptional physical and spiritual qualities, symbolizing their purity and divinity.

One such symbolic attribute mentioned in some Jain texts is that Tirthankaras have white-colored blood. This is not meant to be understood in a literal, biological sense, but rather as a symbol of their absolute purity, non-violence (ahimsa), and freedom from all karma and impurities. The color white is universally associated with purity, and in Jain iconography, it emphasizes the spotless and sinless nature of the Tirthankaras.

This description is found in several Jain scriptures, such as the "Kalpa Sūtra," which details the lives of Tirthankaras and their extraordinary characteristics. The mention of white blood serves as a metaphor for their spiritual perfection and is one of the many auspicious signs (atiśaya) that distinguish Tirthankaras from ordinary beings.

So, in summary: Jain Tirthankaras are said to have white-colored blood as a symbolic representation of their complete purity, freedom from karma, and divine nature, according to Jain scriptures.