The format is the same as drashna's secrets implementation. Create a secret.h and define your secrets like this:
static const char* secrets[] = {"secret1", "secret2", "secret3", "secret4", "secret5"};
You can hookup your encoder functions by defining new encoder states in encoder.h, then in encoder.c assign static variable state your new state depending on your desired condition and add callbacks to encoder_mapping array.
RGB Matrix ledmaps is the future allowing you assign colors to individual keys on every keymap layer.
You can see some examples of my usage in the bottom of keymap.c.
Color defines are just HSV colors wrapped in curly braces, like #define RED { HSV_RED }.