So basically I joined the NOKIA 3310 JAM 6 a few days ago (no pong).
Some of the restrictions you had where the two classic greenish Nokia colors, but the problem was that Pico 8 doesn't have those colors. Lucky for us Pancelor had left us very helpful and detailed instructions, where he covered a buch of thing like changing the thumnail/colors/resolution etc.. Thanks man :)
You should check it out yourself as well nokia html template by pancelor
29,43,83,126,37,83,0,135,81,171,82,54,95,87,79,194,195,199,255,241,232 ,255,0,77,255,163,0,255,236,39,0,228,54,41,173,255,131,118,156,255,119,168,255,204,170
So Export your game like this "export Your_game.html"
then two files should be exported a name.js and a name.html file
then type in folder, this will open the folder where all your pico 8 stuff is being saved
then I recommend you to drag the two files to your desktop for a better view
Note that if you want to upload your game on itch, you have to rename the .html file to index.html
After doing that You open the Your_game.js file in any texteditor. Now you will see a loooot of numbers, kinda like
that:
They contains rgb values for all the colors from 1 to 15 not 0
Now replace both with any string with 15 rgb colors:
(classic Nokia Colors)
You can use any tool to get those colors, I found a those two: make a palette and a useful color converter: hex to rgb etc...
If you want to upload your game up on itch:
Rename your Yourgame.html file to index.html
Zip index.html and Yourgame.js
upload on itch :O