command execute errors

2013-04-20 12:22:56 [WARNING] [MineZ] Task #21 for MineZ v0.5.1 generated an exception
java.lang.NullPointerException
	at com.jordair.gmail.MyZ.utils.Utils.color(Utils.java:383)
	at com.jordair.gmail.MyZ.Listeners.tickListener.doLogout(tickListener.java:133)
	at com.jordair.gmail.MyZ.Listeners.tickListener.run(tickListener.java:126)
	at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftTask.run(CraftTask.java:53)
	at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
	at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:512)
	at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225)
	at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:476)
	at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:409)
	at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)
2013-04-20 12:22:57 [WARNING] [MineZ] Task #21 for MineZ v0.5.1 generated an exception
java.lang.NullPointerException
	at com.jordair.gmail.MyZ.utils.Utils.color(Utils.java:383)
	at com.jordair.gmail.MyZ.Listeners.tickListener.doLogout(tickListener.java:133)
	at com.jordair.gmail.MyZ.Listeners.tickListener.run(tickListener.java:126)
	at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftTask.run(CraftTask.java:53)
	at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
	at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:512)
	at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225)
	at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:476)
	at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:409)
	at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)