The code generation, especially on RISCs, has improved pretty dramatically between 4.8 and 6.2. You can expect to get better code size with a newer toolchain.
That said, there's a good chance it's not too hard to forward port the patches; I'm not aware of any major rearchitecting between 4.8 and 6.2, then again maybe there's been one.
If you dont want to mess with gcc flags in all your projects, add the GCC_COLORS env variable to your shell, like just export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'` to your ~/.bashrc or other shell rc.
What is old about this, the 4.8.5 version of GCC was was released June 2015.