Thank you aioi !! I love your site as well, I've already added your button :3 you might know me for the nukochannel website as well !
Hiya ! I used the CSS "filter" property on each button individually to adjust the color of each. For dark one's I use "filter: invert(100%)" first which inverts the colors, making black turn into white for example. Then I used a mix of hue-rotate(), saturate(), brightness(), and opacity() on an individual basis to adjust it further. Feel free to right click > inspect my page and you'll see all code for yourself :)
then if you also want to remove the filter when you hover the mouse on the buttons, like I did, add a section to your CSS with a ":hover" event and use "filter: none !important;", this will turn off the filters ! For example my code looks like :#buttonmarquee:hover img { filter: none !important; }
aaaaa hi!!!!! i need to get back on here and actually do some work but i feel like i NEVER have enough time in the day to get ANYTHING done T_T smh
PLEASE DO IT, and say its not an april fools joke pls xD that would be a piece of internet history
thank you !