cross platform issues in webpages

I am developing some basic html pages, i 开发者_开发百科am setting colors of text usimg color code #e7eddf

it seems fine in windows but seems different in mac.

Can you explain me why its happening and also suggest me some work around for that??

I am using firefox on both the mac and windows

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Macs use 1.8 gamma by default compared to 2.2 on other OS. This was fixed in Snow Leopard which also uses 2.2 now. Read more here.