I picked purple flowers for this post because I am transplanting a dark purple Wave Petunia hanging basket today.
I have taken pictures of the flowers and depending on the light, they sometimes look blue or lighter purple.
The Medicago sativa is a field flower and is a form of Alfalfa.

All of the pictures are from Wikimedia Commons, except for the first one.

By, TeunSpaans, Netherlands Wikipedia.

MedicagoSativa-CloseUp-hr TeunSpaans nl wikiBy, Radioreg from Vienna Austria.

Radio Tonreg from Vienna Austria WCThe next two pictures are by H. Zell.

Medicago_sativa_003 H. Zell WC360px-Medicago_sativa_002 H. Zell WCTwo pictures by User:Bogdan.

405px-Medicago_sativa_bgiu Bogdan User WC323px-Medicago_sativa_02_bgiu USer Bogdan WCBy, 4028mdk09.

360px-Pflanze_am_Ackerrand 4028mdk09 WCThis last picture is by, Matt Lavin from Bozeman, Montana, USA.

Medicago_sativa_(5183006168) Matt Lavin from Bozeman Montana USA WC