In Arabic if someone says you have light (not heavy) blood, i.e. dam khafif, it’s an expression that means that someone is loveable and funny.
This is a phrase in Shaabi star Hoda’s song Ashoof Feek Youm, which is a translation done in idiomatic english along with transliteration and Arabic script done available for purchase. She calls her lover, “Abu Dam khafif.” The Father of Light blood? Not. Just a funny loveable guy. For more details purchase the translation. Drop me an e-mail at colloquialArabic4@gmail.com