When the recruiter searches Taleo, it's not opening up each attachment to search the text(white or black). The data will be parsed or separated into data fields. Imagine an excel spreadsheet with cell representing data item such as name, street address, city, employer, dates of employment.
It will not look like your resume in MS Word or PDF format. The recruiter will see something like the image below.
Notice how the ATS imported the resume incorrectly. The executive summary was misidentified as an item under work history. There is no "white fonting" here, because the original attachment is not being searched or displayed. The system doesn't open up hundreds of Word documents one-by-one to search, and then aggregate the results.
It's searching a database with the data fields, then displaying the data field in the created template. White fonting doesn't come into play.