You've provided very scant details for your question. Could you list your current Firefox version, your OS, and any privacy or security software in use?

The visual rendering settings in Firefox can be found under about:preferences#content (enter into the address bar like a normal address). The checkbox "Allow pages to choose their own" behind Advanced and Colours should be checked. Note the drop down menu which specifies High Contrast themes - if you use one, Firefox overrides colours, unless you change this yourself.

As a comparison, does Firefox look normal in Safe Mode? https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode#w_how-to-start-firefox-in-safe-mode

It sounds like a case of suppressing the page encoding/layout and possibly blocking images/content.

Firefox version is the latest,windows 7,eset security... This happened after my bios lost the data,and when I updated windows time,it opened like this...the picture uploader doesnt work,its taking forever,(one MUST have pacience with this site)will try again...also,in safe mode was the same,reinstalling didnt work,etc,etc

ESET has a good reputation, so it's probably not that. Windows 7 is also a very stable platform at this point, no update troubles like on W8 and Win10.

The data loss sounds like the culprit here, but what could have happened that not even a reinstall will fix is very puzzling. The Windows theme override mentioned in the layout settings got me thinking though... could you change your theme in Windows itself and see if that helps? If there is interaction here, it might change things - and Windows won't be affected as such if you just uninstall and reinstall Firefox.

Only the text displaying is also a symptom of partial loading (due to bad/slow connection), so if the theme change doesn't work, you could test your connection with www.speedtest.net and www.pingtest.net - just in case.

Just to be extra sure, you could check the Page Info view (right click page, select View Page Info) and see that Load Images is set to Allow. Corrupt settings will do the craziest things, but if you did a thorough uninstall (wiped profiles and everything), then these should be at healthy defaults.

Eset smart Security 9 :

Path: Advanced Setup -- Web and Email --- SSL/TLS
Root certificate then uncheck "Add the root certificate to know browsers"
SSL protocol: Do not scan SSL protocol

Thank you very much "cor-el",it worked perfectly! Now I can go ahead and use my favorite browser (clean and neat looks) without a nag! Thank you!

Glad to see it got sorted. *adds ESET to the naughty list*

And thank you too for your help and effort!