"keeping true to" is correct and usable in written English.
You can use it as a phrase to describe the act of staying loyal to a commitment, belief, or idea. For example, you could say "She kept true to her word and followed through with the promise."
That's what brands are about – keeping true to the promise of the thing in itself".
"We need to figure out how to change minor things while keeping true to who we really are," she said.
And I knew I had to do that while keeping true to Mamet's language, which has its own special meter.
Keeping true to their reputation of refusing to rigidly toe any party line, Vermonters elected Democrats, Republicans and independents.
"It was definitely no easy task to innovate from well-established platform games like Super Mario Brothers while still keeping true to the genre.
Andrew Carmellini, the chef and owner of Locanda Verde in Manhattan, studied cooking in Italy but has gone his own way, while keeping true to the dish's nature.
The threat back home certainly isn't as immediate, but our collective addiction to fossil fuels is keeping true independence, freedom and security just out of our reach.
No doubt there is some benefit to be had, fundraising-wise, by keeping true believers fired up.
Our purpose is to remove CGH noise in whole frequency while keeping true signal by using bivariate model.
Mill's claim that the value of freedom of expression lies in keeping true beliefs from becoming dogmatic reflects his view that freedoms of thought and discussion are necessary for fulfilling our natures as progressive beings (OL II 20).
Remember that the army who wins is the one that shares the same spirit throughout all its ranks, keeping true and remaining consistent.
