I'm sorry but I'm forced to ask;
Why do you care? What is it about this string of text that you find so objectionable?
Now if you do have a good reason to want it removed or at least unseen, I guess you could do as
cowski has suggested and change the 'Selection' color. However that will only prove effective if you're NOT using the Monochrome display option for your drawings. I say this since you originally asked how can you set the color to 'white' which suggests that you are using a Monochrome Drawing display since that is generally the only place where the Drawing background is 'white' and I assume that you were going to use this color change to effectively 'turn-off' the display of the text. Unfortunately, if you ARE using Monochrome display, changing the 'Selection' color will NO effect on this string of text. You'd have to change the 'Foreground' color to 'White' which is NOT going to get you anywhere, trust me ;-)
Now if you're running NX 8.0 or newer, there is something that you can do to at lesat mitigate (make it less offensive) the presence of this string of text. Just go that same place that
cowski suggested...
Preferences -> Visualization -> Color/Font
...and at the bottom of the page you can change the size and the font used for any on-screen text, including this note in the bottom left corner of the screen. Just set the size to the smallest available, make sure you keep it set to 'Regular' and then change the font to one of the smaller, lightweight typefaces, such as 'Cordia New' or one of the so-called 'UPC' fonts, such as 'IrisUPC' or 'FreeiaUPC'. Now this won't actually remove the text, but it will make it as small and unobtrusive as possible.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.