The phrase "different tone" means a change in the way something is expressed or understood. It could suggest a shift in the feeling, attitude, or style of communication. Full definition
We like the idea of mixing different tones of brown and red to play off the warm oatmeal color of the dress. (effortlesslywithroxy.com)
A loose shirt and a pair of tailored pants in different tones of grey and classic black pumps are the key - pieces you need copy to her outfit. (blog.netrobe.com)
For example, both the price and the availability of credit to the high grade and high yield bond markets have assumed a very different tone from earlier in this decade. (bigpicture.typepad.com)