Tutorial How to change clock color

First, decompile your systemUI

edit smali to unlock font color,
go to SystemUI\smali\com\android\systemui\statusbar\Clock.smali
find this code

    .line 108
    const/4 v1, -0x1

    invoke-virtual {p0, v1}, Lcom/android/systemui/statusbar/Clock;->setTextColor(I)V

if you understand smali code, you can set font color from that smali
If you are not understand about smali code,
follow this method, dont worry, this fine

Delete that smali code
then go to SystemUI\res\layout\status_bar.xml
find this code

<com.android.systemui.statusbar.Clock android:textAppearance="@android:style/TextAppearance.StatusBar.Icon" android:gravity="left|center" android:paddingRight="6.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />

just add this code to line to change font color....
android:textColor="#Hexacolor"

ex: you want ics blue color
<com.android.systemui.statusbar.Clock android:textAppearance="@android:style/TextAppearance.StatusBar.Icon" android:textColor="#ff39bbe5" android:gravity="left|center" android:paddingRight="6.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />

just compile SystemUI