Photoshop is great if you want to construct sprite overlays to your NES backgrounds or draw cutscenes and make use of layers or drawing tools while doing so.
Here’s a complete NES master palette swatch (each named after its NES colour ID) so you don’t have to construct it from scratch.
Note that the two white swatches are there to remind you that the NES does have two identical whites in the 0 column, which can be used for preserving text whiteness while dimming the rest of screen, for example. It also helps to keep the colours tidy and easy to navigate in the swatch bar. While there are many black definitions (some with a minute difference in actual darkness) in the NES master palette, this one only keeps the one which is regarded ”safe to use” on all monitors and setups.
Tip: It is also possible to load the swatch as a palette index definition in indexed colour mode, which is often very useful and generally safer / less tedious to be in when doing NES graphics in photoshop.
Regrettably, adobe never thought to combine indexed mode with layering functionality, so i usually keep two work files side by side for carrying out actions in whatever mode is more suitable, and thereby preserve layers.
The swatch is modelled after Firebrandx ”classic nes” palette, which offers a great accuracy/neutrality while also maintaining the blues and greens identifiable, which is sometimes a problem with some palettes for some emulators and drawing tools out there.
Firebrandx:s homepage with several additional palette captures can be found here.