mybb importer [color] bbcode

bbcode [color] is not converted perfectly after migration, here is the original BBM code:

[url=http:test.com][color=#FF0000]Orang [color=#4682B4][size=x-large]BANDUNG [/size][/color]Absen Sini Yukkkk[/color][/url]

and here is the result in WBB

CMIIW, it seems WSC can not handle a [bbcode] inside [bbcode], so the inside bbcode will always be ignored, and rendered as raw code.