The desktop icon for the installer is currently using a Java Update icon (orange). It should use the standard Java installer icon.
For example, the 48px version to use is here:
http://jre.us.oracle.com/java/re/j2se/7/promoted/latest/ws/deploy/src/common/share/classes/com/sun/deploy/resources/image/java48.png
32px version:
http://jre.us.oracle.com/java/re/j2se/7/promoted/latest/ws/deploy/src/common/share/classes/com/sun/deploy/resources/image/java32.png
16px version:
http://jre.us.oracle.com/java/re/j2se/7/promoted/latest/ws/deploy/src/plugin/win32/graphics/java-icon.ico