Using custom item strings in custom villager shops causes crash

Using two filters. Modify item strings and create shops.

I've modified an item name and colored it. When applied to a villager shop the game crashes when a trade is made.

Crash report:

Minecraft Crash Report ----
// Who set us up the TNT?

Time: 12/11/13 9:08 PM
Description: Rendering screen

java.lang.NullPointerException: Rendering screen
at bcd.a(SourceFile:76)
at beb.a(SourceFile:165)
at bll.b(SourceFile:851)
at azd.ad(SourceFile:780)
at azd.e(SourceFile:704)
at net.minecraft.client.main.Main.main(SourceFile:103)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at bcd.a(SourceFile:76)
at beb.a(SourceFile:165)

– Screen render details –
Details:
Screen name: beb
Mouse location: Scaled: (282, 82). Absolute: (1130, 689)
Screen size: Scaled: (480, 255). Absolute: (1920, 1018). Scale factor of 4

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [bje['Jragon14'/23007, l='MpServer', x=1729.56, y=23.62, z=188.73]]
Chunk stats: MultiplayerChunkCache: 225, 225
Level seed: 0
Level generator: ID 01 - flat, ver 0. Features enabled: false
Level generator options:
Level spawn location: World: (1667,4,104), Chunk: (at 3,0,8 in 104,6; contains blocks 1664,0,96 to 1679,255,111), Region: (3,0; contains chunks 96,0 to 127,31, blocks 1536,0,0 to 2047,255,511)
Level time: 350310 game time, 15190 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
Forced entities: 34 total; [bje['Jragon14'/23007, l='MpServer', x=1729.56, y=23.62, z=188.73], rf['entity.ItemFrame.name'/22973, l='MpServer', x=1726.06, y=23.50, z=195.50], rf['entity.ItemFrame.name'/22975, l='MpServer', x=1726.06, y=23.50, z=203.50], rf['entity.ItemFrame.name'/22974, l='MpServer', x=1726.06, y=23.50, z=199.50], rf['entity.ItemFrame.name'/22969, l='MpServer', x=1684.50, y=22.50, z=150.06], rf['entity.ItemFrame.name'/22968, l='MpServer', x=1685.50, y=23.50, z=150.06], rf['entity.ItemFrame.name'/22967, l='MpServer', x=1684.50, y=23.50, z=150.06], rf['entity.ItemFrame.name'/22986, l='MpServer', x=1742.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22987, l='MpServer', x=1743.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22984, l='MpServer', x=1740.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22985, l='MpServer', x=1741.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22990, l='MpServer', x=1732.94, y=23.50, z=193.50], rf['entity.ItemFrame.name'/22991, l='MpServer', x=1732.94, y=23.50, z=197.50], rf['entity.ItemFrame.name'/22988, l='MpServer', x=1736.50, y=22.50, z=187.94], xh['Villager'/22989, l='MpServer', x=1729.50, y=22.00, z=186.50], rf['entity.ItemFrame.name'/22976, l='MpServer', x=1726.06, y=23.50, z=207.50], rf['entity.ItemFrame.name'/22977, l='MpServer', x=1726.06, y=23.50, z=211.50], rf['entity.ItemFrame.name'/22982, l='MpServer', x=1738.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22983, l='MpServer', x=1739.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22980, l='MpServer', x=1736.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22981, l='MpServer', x=1737.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/23002, l='MpServer', x=1732.94, y=23.50, z=209.50], wf['entity.MinecartSpawner.name'/23001, l='MpServer', x=1739.50, y=23.34, z=206.50], rf['entity.ItemFrame.name'/23000, l='MpServer', x=1732.94, y=23.50, z=207.50], rf['entity.ItemFrame.name'/23006, l='MpServer', x=1745.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/23005, l='MpServer', x=1744.50, y=23.50, z=185.06], rf['entity.ItemFrame.name'/22995, l='MpServer', x=1732.94, y=23.50, z=199.50], rf['entity.ItemFrame.name'/22994, l='MpServer', x=1732.94, y=23.50, z=195.50], rf['entity.ItemFrame.name'/22993, l='MpServer', x=1732.94, y=23.50, z=205.50], rf['entity.ItemFrame.name'/22992, l='MpServer', x=1732.94, y=23.50, z=201.50], wf['entity.MinecartSpawner.name'/22999, l='MpServer', x=1739.50, y=23.34, z=194.50], wf['entity.MinecartSpawner.name'/22998, l='MpServer', x=1739.50, y=23.34, z=202.50], rf['entity.ItemFrame.name'/22997, l='MpServer', x=1732.94, y=23.50, z=203.50], wf['entity.MinecartSpawner.name'/22996, l='MpServer', x=1739.50, y=23.34, z=198.50]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Integrated singleplayer server
Stacktrace:
at biz.a(SourceFile:284)
at azd.b(SourceFile:1951)
at azd.e(SourceFile:713)
at net.minecraft.client.main.Main.main(SourceFile:103)

– System Details –
Details:
Minecraft Version: 1.7.2
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 81940816 bytes (78 MB) / 223072256 bytes (212 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
AABB Pool Size: 26916 (1507296 bytes; 1 MB) allocated, 3 (168 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.7.2
LWJGL: 2.9.0
OpenGL: AMD RADEON HD 6450 GL version 4.0.10243 Compatibility Profile Context, ATI Technologies Inc.
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 349 (19544 bytes; 0 MB) allocated, 35 (1960 bytes; 0 MB) used
Anisotropic Filtering: Off (1)