Logically invert the pin?

Check out https://www.espruino.com/Reference#l_SPI­_send4bit

The old way of doing neopixels on STM32 was:

SPI1.setup({baud:3200000, mosi:B5});
SPI1.send4bit(leds, 0b0001, 0b0011); // send to the lights

and that's basically what still happens under the hood.

If you tried:

SPI1.send4bit(leds, 0b1110, 0b1100);

instead then it might invert everything for you.