Theme and color

<date-picker color="#5c6bc0" />

<date-picker color="#e91e63" />
<date-picker color="#e91e63" simple />

<date-picker color="#7b1fa2" />

<date-picker color="#1e88e5" />

<date-picker color="#03a9f4" />

<date-picker color="#00acc1" />

<date-picker color="#ff9800" />

<date-picker color="dimgray" />