Text color showing different than what I used

The email I sent this morning looked fine in constant contact & in 2 test emails ... Now after I have sent it - a portion of a section isn't showing up when the email is opened because the text color is now white... ( it is black in the original fie sent ) 

Please advise ....  this is quite embarrassing when it looks at though someone wasn't paying attention and sent something out that is  incomplete/ imcorrect!