I like using the pico-8 palette for general pixel art because of the designers intent on making the palette as flexible as possible with the limited colors used; however I feel this philosophy isn't taken as well for the secret palette, which I use alongside the default. The secret palette kinda feels like its just making variations on the default palette rather than filling in its deficiencies (although it does a great job usually) one color I would like to see added is a bright cyan-like color, because light grey is quite jarring against a very solid cyan. light cyan would make what I would consider a very essential highlight for blue
Id suggest replacing deep brown (128), since there are already plenty of brown/orange colors, and purple makes a good shadow to brown. I even remade the palette in the original spirit, while adding the color: 80ffc8 (R 128, G 255, B 200) This can definitely be tweaked. Thanks for considering my suggestion.