diff --git a/gearslip/src/main/java/app/seb3thehacker/gearslip/car/PlayerParts.kt b/gearslip/src/main/java/app/seb3thehacker/gearslip/car/PlayerParts.kt
index 9a529ba..e0627d5 100644
--- a/gearslip/src/main/java/app/seb3thehacker/gearslip/car/PlayerParts.kt
+++ b/gearslip/src/main/java/app/seb3thehacker/gearslip/car/PlayerParts.kt
@@ -145,7 +145,7 @@ internal fun PlayModeRow(
         // Gearslip's own stand in for apps that report a heart rating or shuffle and repeat modes.
         val likeAction = now.likeAction
         if (likeAction != null) {
-            CustomActionButton(likeAction, media, size, toggle = true)
+            CustomActionButton(likeAction, media, size, on = liked == true)
         } else {
             GsIconButton(
                 if (liked == true) Icons.Filled.Favorite else Icons.Filled.FavoriteBorder,
@@ -158,7 +158,7 @@ internal fun PlayModeRow(
         }
         val shuffleAction = now.shuffleAction
         if (shuffleAction != null) {
-            CustomActionButton(shuffleAction, media, size, toggle = true)
+            CustomActionButton(shuffleAction, media, size, on = shuffleAction.on)
         } else {
             GsIconButton(
                 MediaIcons.Shuffle, stringResource(if (shuffleOn) R.string.player_shuffle_off else R.string.player_shuffle_on),
@@ -170,7 +170,7 @@ internal fun PlayModeRow(
         }
         val repeatAction = now.repeatAction
         if (repeatAction != null) {
-            CustomActionButton(repeatAction, media, size, toggle = true)
+            CustomActionButton(repeatAction, media, size, on = repeatAction.on)
         } else {
             GsIconButton(
                 if (modes.repeat == PlaybackStateCompat.REPEAT_MODE_ONE) MediaIcons.RepeatOne else MediaIcons.Repeat,
@@ -191,12 +191,12 @@ internal fun PlayModeRow(
  * not Gearslip's, so it's loaded from there. Its name stands in if the icon won't load.
  */
 @Composable
-private fun CustomActionButton(action: CustomAction, media: CarMedia, size: Dp, toggle: Boolean = false) {
+private fun CustomActionButton(action: CustomAction, media: CarMedia, size: Dp, on: Boolean = false) {
     val icon = rememberActionIcon(action)
     GsIconBox(
         onClick = { media.custom(action) },
         modifier = Modifier.size(size),
-        colors = gsColors(if (toggle && action.on) GsTone.Primary else GsTone.Neutral),
+        colors = gsColors(if (on) GsTone.Primary else GsTone.Neutral),
     ) {
         if (icon != null) {
             Icon(icon, action.name, Modifier.size(size * 0.52f))
diff --git a/gearslip/src/main/java/app/seb3thehacker/gearslip/media/CarMedia.kt b/gearslip/src/main/java/app/seb3thehacker/gearslip/media/CarMedia.kt
index 4941532..f96228c 100644
--- a/gearslip/src/main/java/app/seb3thehacker/gearslip/media/CarMedia.kt
+++ b/gearslip/src/main/java/app/seb3thehacker/gearslip/media/CarMedia.kt
@@ -44,15 +44,27 @@ class MediaEntry(
     val group: String? = null,
 )
 
-/** [icon] is a drawable id inside the media app's own package, not Gearslip's; 0 for none. */
-class CustomAction(val id: String, val name: String, val extras: Bundle?, val icon: Int = 0, val iconName: String = "") {
+/**
+ * [icon] is a drawable id inside the media app's own package, not Gearslip's; 0 for none.
+ * [hasOutline] says the app also has an outline of the same icon (ic_heart beside ic_heart_outline).
+ */
+class CustomAction(
+    val id: String,
+    val name: String,
+    val extras: Bundle?,
+    val icon: Int = 0,
+    val iconName: String = "",
+    val hasOutline: Boolean = false,
+) {
     /**
      * Whether a toggle like heart or shuffle is on, read from the icon's name - Tidal swaps
      * ic_favorite for ic_favorite_filled and ic_shuffle for ic_shuffle_active, and keeps the
      * button's name the same. Whole words only, so "inactive" doesn't count as "active".
+     * Metrolist swaps ic_heart_outline for a plain ic_heart, so a plain icon that has an outline
+     * twin counts as on too.
      */
     val on: Boolean
-        get() = iconName.lowercase().split('_', '.', '-').any { it in ON_WORDS }
+        get() = hasOutline || iconName.lowercase().split('_', '.', '-').any { it in ON_WORDS }
 
     private companion object {
         val ON_WORDS = setOf("filled", "fill", "active", "on", "selected", "checked", "enabled", "solid", "one", "all")
@@ -118,8 +130,8 @@ class NowPlaying(
      * only says which way it goes next by its name ("Remove from Liked Songs"), so that's read.
      */
     val liked: Boolean?
-        get() = heart ?: likeAction?.name?.let { name ->
-            listOf("remove", "unlike", "unfav", "unheart").any { name.contains(it, ignoreCase = true) }
+        get() = heart ?: likeAction?.let { action ->
+            action.on || listOf("remove", "unlike", "unfav", "unheart").any { action.name.contains(it, ignoreCase = true) }
         }
 
     val playing get() = state == PlaybackState.STATE_PLAYING || state == PlaybackState.STATE_BUFFERING
@@ -392,7 +404,10 @@ class CarMedia(private val context: Context) {
             speed = state?.playbackSpeed ?: 1f,
             updatedAt = state?.lastPositionUpdateTime ?: 0,
             actions = state?.actions ?: 0,
-            custom = withNextChapter(state?.customActions.orEmpty().map { CustomAction(it.action, it.name.toString(), it.extras, it.icon, iconName(it.icon)) }),
+            custom = withNextChapter(state?.customActions.orEmpty().map {
+                val iconName = iconName(it.icon)
+                CustomAction(it.action, it.name.toString(), it.extras, it.icon, iconName, hasOutline(it.icon, iconName))
+            }),
             error = state?.errorMessage?.toString(),
             activeQueueItemId = state?.activeQueueItemId ?: MediaSession.QueueItem.UNKNOWN_ID.toLong(),
             heart = if (controller?.ratingType == Rating.RATING_HEART) {
@@ -405,7 +420,6 @@ class CarMedia(private val context: Context) {
 
     private var appResources: Pair<String, android.content.res.Resources?>? = null
 
-    /** The icon's resource name in the app's package, or "" when it can't be read. */
     /**
      * AntennaPod takes a Next chapter command whenever it's playing, but offers the button only
      * when the driver turns it on in its notification settings. Gearslip offers it either way,
@@ -424,16 +438,30 @@ class CarMedia(private val context: Context) {
     private fun resourcesOf(pkg: String): android.content.res.Resources? {
         if (appResources?.first != pkg) {
             appResources = pkg to runCatching { context.packageManager.getResourcesForApplication(pkg) }.getOrNull()
+            outlines.clear()
         }
         return appResources?.second
     }
 
+    /** The icon's resource name in the app's package, or "" when it can't be read. */
     private fun iconName(icon: Int): String {
         val pkg = controller?.packageName ?: return ""
         val res = resourcesOf(pkg) ?: return ""
         return runCatching { res.getResourceEntryName(icon) }.getOrDefault("")
     }
 
+    /** Whether each icon has an outline twin, by icon id: looked up once, since state changes often. */
+    private val outlines = HashMap<Int, Boolean>()
+
+    private fun hasOutline(icon: Int, name: String): Boolean {
+        val pkg = controller?.packageName ?: return false
+        val res = resourcesOf(pkg) ?: return false
+        if (name.isEmpty() || OUTLINE_WORDS.any { name.contains(it, ignoreCase = true) }) return false
+        return outlines.getOrPut(icon) {
+            OUTLINE_WORDS.any { res.getIdentifier("${name}_$it", "drawable", pkg) != 0 }
+        }
+    }
+
     private var loggedButtons: String? = null
 
     /** The app's own buttons, by id, name and icon, each time they change. */
@@ -822,6 +850,8 @@ class CarMedia(private val context: Context) {
         /** How long an app gets to start playing a search before Gearslip says it didn't. */
         const val SEARCH_WAIT_MS = 6_000L
         const val SEARCH_NOTICE_MS = 6_000L
+        /** How apps name the empty version of an icon. */
+        val OUTLINE_WORDS = listOf("outline", "outlined", "border", "empty")
     }
 }