diff --git a/base/src/main/java/de/staropensource/sosengine/base/classes/ShortcodeParserSkeleton.java b/base/src/main/java/de/staropensource/sosengine/base/classes/ShortcodeParserSkeleton.java
index a782076..5ad2d52 100644
--- a/base/src/main/java/de/staropensource/sosengine/base/classes/ShortcodeParserSkeleton.java
+++ b/base/src/main/java/de/staropensource/sosengine/base/classes/ShortcodeParserSkeleton.java
@@ -24,11 +24,10 @@ import de.staropensource.sosengine.base.logging.LoggerInstance;
 import de.staropensource.sosengine.base.types.CodePart;
 import de.staropensource.sosengine.base.types.logging.LogIssuer;
 import lombok.Getter;
-import org.fusesource.jansi.Ansi;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.LinkedList;
+import java.util.Locale;
 
 /**
  * The base skeleton for implementing a shortcode parser.
@@ -71,7 +70,7 @@ public abstract class ShortcodeParserSkeleton {
      */
     @NotNull
     @Getter
-    protected final List<String> components;
+    protected final LinkedList<String> components;
 
     /**
      * Constructs this class.
@@ -92,8 +91,8 @@ public abstract class ShortcodeParserSkeleton {
      * @since v1-alpha1
      */
     @NotNull
-    private List<@NotNull String> parse(@NotNull String string) {
-        List<String> components = new ArrayList<>();  // List of components
+    protected LinkedList<@NotNull String> parse(@NotNull String string) {
+        LinkedList<String> components = new LinkedList<>();  // List of components
         boolean tagActive = false;  // Indicates that a tag is being parsed
         String part = "";  // Current part. May be a tag, may be regular text
 
@@ -109,26 +108,36 @@ public abstract class ShortcodeParserSkeleton {
                     if (part.startsWith("fg:")) {
                         // Print debug message
                         if (EngineConfiguration.getInstance().isDebugShortcodeConverter())
-                            try {
-                                System.out.println(getClass().getName() + "#" + string.hashCode() + " tag=fg data=" + part.substring(3).toUpperCase() + " enum=" + Ansi.Color.valueOf(part.substring(3).toUpperCase()));
-                            } catch (IllegalArgumentException ignored) {
-                                System.out.println(getClass().getName() + "#" + string.hashCode() + " tag=fg data=" + part.substring(3).toUpperCase() + " enum=<invalid>");
-                            }
+                            System.out.println(getClass().getName() + "#" + string.hashCode() + " tag=fg data=" + part.substring(3).toUpperCase());
 
-                        components.add("COLOR:FOREGROUND:" + part.substring(3).toUpperCase());
+                        if (isValidColor(part.substring(3).toUpperCase()))
+                            components.add("COLOR:FOREGROUND:" + part.substring(3).toUpperCase());
+                        else {
+                            // Complain about invalid shortcode
+                            if (EngineConfiguration.getInstance().isErrorShortcodeConverter())
+                                logger.sarn("Invalid shortcode: " + part);
+
+                            // Convert tag regular text
+                            components.add("TEXT:" + "<" + part + ">");
+                        }
                     }
 
                     // bg:*
                     else if (part.startsWith("bg:")) {
                         // Print debug message
                         if (EngineConfiguration.getInstance().isDebugShortcodeConverter())
-                            try {
-                                System.out.println(getClass().getName() + "#" + string.hashCode() + " tag=bg data=" + part.substring(3).toUpperCase() + " enum=" + Ansi.Color.valueOf(part.substring(3).toUpperCase()));
-                            } catch (IllegalArgumentException ignored) {
-                                System.out.println(getClass().getName() + "#" + string.hashCode() + " tag=bg data=" + part.substring(3).toUpperCase() + " enum=<invalid>");
-                            }
+                            System.out.println(getClass().getName() + "#" + string.hashCode() + " tag=bg data=" + part.substring(3).toUpperCase());
 
-                        components.add("COLOR:BACKGROUND:" + part.substring(3).toUpperCase());
+                        if (isValidColor(part.substring(3).toUpperCase()))
+                            components.add("COLOR:BACKGROUND:" + part.substring(3).toUpperCase());
+                        else {
+                            // Complain about invalid shortcode
+                            if (EngineConfiguration.getInstance().isErrorShortcodeConverter())
+                                logger.sarn("Invalid shortcode: " + part);
+
+                            // Convert tag regular text
+                            components.add("TEXT:" + "<" + part + ">");
+                        }
                     }
 
                     // bold
@@ -181,16 +190,6 @@ public abstract class ShortcodeParserSkeleton {
                         components.add("ATTRIBUTE:BLINK");
                     }
 
-                    // underline
-                    else if (part.equals("negative")) {
-                        // Print debug message
-                        if (EngineConfiguration.getInstance().isDebugShortcodeConverter())
-                            System.out.println(getClass().getName() + "#" + string.hashCode() + " tag=negative");
-
-                        // Insert attribute
-                        components.add("ATTRIBUTE:NEGATIVE");
-                    }
-
                     // reset
                     else if (part.equals("reset")) {
                         // Print debug message
@@ -251,4 +250,20 @@ public abstract class ShortcodeParserSkeleton {
 
         return components;
     }
+
+    /**
+     * Checks the supplied color tag and returns if it's valid.
+     *
+     * @since v1-alpha2
+     */
+    private boolean isValidColor(@NotNull String color) {
+        switch (color.toLowerCase(Locale.ROOT)) {
+            case "black", "white", "red", "green", "blue", "yellow", "magenta", "cyan" -> {
+                return true;
+            }
+            default -> {
+                return false;
+            }
+        }
+    }
 }