Your error is unrelated to the resolution. As the error message says:
LVGL *must* be compiled with LV_COLOR_DEPTH=16 (currently LV_COLOR_DEPTH=32.
Anyway: 32 bits color depth (per pixel, not per channel) x 480 x 320 = 600kB . Bytes, not bits. That´s 300kB if you use 16 bits color depth. The RP2040 has 264kB SRAM, and you need some for running micropython.
My guess is that if you really want to use the RP2040 with this resolution you might want to get down to 8 bits per pixel (150kB) -if supported by the driver- and/or drop micropython for pure (C) LVGL.
Or use another target like ESP32 with (slow) SPIRAM. Or better, a beefy STM32H7 with 1MB of RAM.
But you´re definitely -i think- not going to get high-resolution +high framerate, micropython on the RP2040.
Or switch to a comparable size display with half the resolution.
See here: ESP32 320x480 low FPS animating - #10 by Marian_M
and here: Colors — LVGL documentation
@all: If something i wrote is inexact, please correct me.