the Prophet said about a man who had sexual intercourse with his wife while she is menstruating: "He should give half a Dinar in charity."  

عَنِ النَّبِيِّ ﷺ فِي الرَّجُلِ يَقَعُ عَلَى امْرَأَتِهِ وَهِيَ حَائِضٌ قَالَ يَتَصَدَّقُ بِنِصْفِ دِينَارٍ  

the Prophet said: "When the blood is red then (give) a Dinar. And when the blood is yellow then half Dinar."  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا كَانَ دَمًا أَحْمَرَ فَدِينَارٌ وَإِذَا كَانَ دَمًا أَصْفَرَ فَنِصْفُ دِينَارٍ