Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Calendar, Muhurta Elements
कालमानं मुहूर्ताङ्गानि च
इंदुज्ञजीवशुक्राणां वासराः सर्वकर्मसु ।फलदास्त्वितरे क्रूरे कर्मस्वभिमतप्रदाः ॥ १६१ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 161.
The days of the Moon, Mercury, Jupiter and Venus give results in every kind of work. The days of the other, cruel planets give the wished result in cruel work.
Simple meaning: The Moon, Mercury, Jupiter and Venus days suit all work. The other days suit only harsh work.
रक्तवर्णौ रविश्चंद्रौ गौरो भौमस्तु लोहितः ।
Each planet has a colour: Sun red, Moon white, Mars blood red, Mercury green, Jupiter yellow, Venus white.
कृष्णः सौरिः स्ववारेषु स्वस्ववर्णक्रिया हिताः ।
Saturn is black. Work in a planet's colour suits its own day. Bad-time numbers for Sunday and Monday follow.
बाणाग्निलोचनानिह्यवेदबाहुशिलीमुखाः ।
These numbers mark the bad parts of the day for Tuesday to Saturday.