How to color and alignment spinner item on android?

Use a custom view for that, and specify by calling:

a.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

Note that you have to use your own view here: R.id.my_simple_spinner_dropdown_item

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@android:id/text1"
    style="?android:attr/spinnerItemStyle"
    android:singleLine="true"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:ellipsize="marquee" />