Yes, that is true. But I believe that most of the 'minor' changes to the Tardis exterior over time were either due to real world reasons such as somewhat 'unloving' repairs to wear & tear on the original prop, or constructing a new slightly-different prop without much attention to the specs of the previous prop. And the changes were introduced with no fanfare, EXCEPT for the reveal of the shiny new exterior after the Tardis repaired herself following the Doctor's explosive regeneration into Eleven.
I have learned from my fellow BBSers to be suspicious about some of these statements from unidentified sources. So I don't think we'll get a Happiness Patrol pink Tardis. But actually announcing a 'new look' is curious. For me, this is similar to the concept of a 'new look' 1927 Ford Model T or a 'new look' 1940 Spitfire fighter(?).