These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] app-portage/conf-update-1.0.3-r1::gentoo  USE="-colordiff" 18 KiB

Total: 1 package (1 new), Size of downloads: 18 KiB