convert #RRGGBB hex value to #AARRGGBB

What value would have #414141 as #AARRGGBB and what abo开发者_C百科ut #52b531? How can I convert this using PHP?

Regards,

Pentium10

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AA is the Alpha channel, and a straight conversion would be to set AA to FF to make it full opaque:

#414141 becomes #FF414141 

(Just to add: In some implementations it means the amount of Transparency where 00 means complete opaque and FF means fully transparent. In that case, #00414141 would be correct. But I think that is the exception)