This uberasm code allows you to apply a transition animation of Global Palette Effect to the palettes 
and fixed color.

For that, you need first to create a palette effect using Palette Effect Creator:

https://snestorage.com/files/PaletteEffectCreator.php

Then put the palette effect on Dynamic X's PaletteEffects folder and installa Dynamic X.

You can select if the fixed color is affected or which palettes are affected changing the following
constants on the .asm file:

;Change this to enable the effect in a specific palette or fixed color
!P0 = 1
!P1 = 1
!P2 = 1
!P3 = 1
!P4 = 1
!P5 = 1
!P6 = 1
!P7 = 1

!P8 = 1
!P9 = 1
!PA = 1
!PB = 1
!PC = 1
!PD = 1
!PE = 1
!PF = 1

!EnableFixedColor = 1

Also you must change the palette effects here:

;Color Effect
!StartingPaletteEffetID = !PaletteEffectIDNight0
!EndPaletteEffetID = !PaletteEffectIDNight16

You can replace !PaletteEffectIDDecreaseSaturation31 by the palette effect that you want.
The defines with the effects are saved on the file DynamicXDefines.

You can also change the delay between each palette effect change here:

!Delay = $03 ; Can be values $00, $01, $03, $07, $0F, $1F, $3F, $7F and $FF