text color is different in 2 documents

As has been said it looks like the brighter blue document is probably set for RGB while the duller blue is a CMYK document. A quick way to check what color space your document is set for is through the Document Setup dialog window (File>Document Setup). If the pull-down menu under "Intent:" is set for Web or Mobile then the document has an RGB color space. If it's set for Print then the file is CMYK.

I agree with @Test Screen Name 

Another tip: If you're looking for transparency in InDesign, choose Window > Output > Flattener Preview. In the Highlight menu, select Transparent Objects. Transparency will be highlighted in red.

My first guess would be that document 1

(a) has a transparency blend space of CMYK and

(b) has, somewhere on this page, transparency (not involving the text, doesn't matter).

If you aren't designing for print, fix the transparency blend space.