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

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.