With the new theming in AppCompat, a lot of assets are tinted automatically for you via theme attributes. That has often led me to wonder "where the hell did this color come from?" You can replace your normal theme with this debug theme to help figure out the source of that color.

themes-debug.xml

<!-- You can change the parent around to whatever you normally use -->
<style name="DebugColors" parent="Theme.AppCompat">

    <!-- System colors -->
    <item name="android:windowBackground">@color/__debugWindowBackground</item>

    <item name="android:colorPressedHighlight">#FF4400</item>
    <item name="android:colorLongPressedHighlight">#FF0044</item>
    <item name="android:colorFocusedHighlight">#44FF00</item>
    <item name="android:colorActivatedHighlight">#00FF44</item>
    <item name="android:colorMultiSelectHighlight">#4400FF</item>

    <item name="android:statusBarColor">#FFF000</item>
    <item name="android:navigationBarColor">#000FFF</item>

    <item name="android:colorForeground">#440000</item>
    <item name="android:colorForegroundInverse">#004400</item>
    <item name="android:colorBackground">#444400</item>
    <item name="android:colorBackgroundCacheHint">#440044</item>

    <item name="android:textColorPrimary">#FFFF00</item>
    <item name="android:textColorSecondary">#FF00FF</item>
    <item name="android:textColorTertiary">#00FFFF</item>

    <item name="android:textColorPrimaryInverse">#CCCC00</item>
    <item name="android:textColorSecondaryInverse">#CC00CC</item>
    <item name="android:textColorTertiaryInverse">#00CCCC</item>

    <item name="android:textColorPrimaryDisableOnly">#FFCC00</item>
    <item name="android:textColorPrimaryInverseDisableOnly">#FF00CC</item>

    <item name="android:textColorPrimaryNoDisable">#CCFF00</item>
    <item name="android:textColorSecondaryNoDisable">#00FFCC</item>

    <item name="android:textColorPrimaryInverseNoDisable">#CC00FF</item>
    <item name="android:textColorSecondaryInverseNoDisable">#00CCFF</item>

    <item name="android:textColorHint">#FF8800</item>
    <item name="android:textColorHintInverse">#FF0088</item>

    <item name="android:textColorHighlight">#88FF00</item>
    <item name="android:textColorHighlightInverse">#00FF88</item>

    <item name="android:textColorLink">#8800FF</item>
    <item name="android:textColorLinkInverse">#0088FF</item>

    <item name="android:textColorAlertDialogListItem">#444444</item>

    <!-- Color palette (via app-compat) -->
    <item name="colorPrimary">#FF0000</item>
    <item name="colorPrimaryDark">#00FF00</item>
    <item name="colorAccent">#0000FF</item>

    <item name="colorControlNormal">#CC0000</item>
    <item name="colorControlActivated">#00CC00</item>
    <item name="colorControlHighlight">#0000CC</item>

    <item name="colorButtonNormal">#880000</item>
    <item name="colorSwitchThumbNormal">#008800</item>

    <!-- Random other things found in app-compat -->
    <item name="actionMenuTextColor">#440000</item>
    <item name="editTextColor">#004400</item>
    <item name="textColorSearchUrl">#000044</item>

</style>

<!-- Also needed, since windowBackground is a reference, not a color -->
<color name="__debugWindowBackground">#888888</color>

Best gist of the week!

Saved a lot of hours!

Fantastic idea.

Updating this with new material-components lib attributes would be awesome :)

Good