A command block has colored text [E.g. Yellow] with a /say command. When it is triggered, only the first word is yellow, and the rest of the sentence is white in color[default]. This bug only surfaced in 1.7.2.
Step 1. Put down a command block and type a /say command. [E.g. "/say hello guys!" ].
Step 2. Use a world editor [preferably MCEdit or WorldEdit] to give the text a color.
Step 3. Supply it a redstone signal. The bug should replicate itself.
-This bug is only present in 1.7.2. It did not appear in previous versions.
-Although in the command block console, the text shows the whole sentence colored, only the first word is colored when the command block is activated.