i have activities which i themed with my custom theme, but for spinner i choosed to style it with Appcompat v21 but i got this :
Since you are using AppCompat-v21, you can take advantage of the new material design styles attributes:
colorPrimary: your app branding color for the app bar, applies to action bar
colorPrimaryDark: darker variant for the status bar and contextual app bars
colorAccent: lets you define bright complement to the primary branding color. By default, this is the color applied to framework controls (via colorControlActivated)
colorControlNormal: color applied to framework controls in their normal state
colorControlActivated: applied to framework controls in their activated
Here is an example for you
styles.xml
colors.xml
#ff0000ff
#ff0000af
#870000ff
#ffffffff
Here is how it looks
Hope this helps.