unsigned int ObjectAddress = 0xFFFFFFFF;
unsigned int BMDAddress = 0xFFFFFFFF;
// Replace XXXXXXXX with the address just after the call to 0x02016FD4 and YY with the overlay in which that address is contained
void hook_XXXXXXXX_ov_YY()
{
asm
(
"ldr r2, =ObjectAddress \t\n"
"str r4, [r2] \t\n" // In my case r4 held the object's address but this will differ
"ldr r2, =BMDAddress \t\n"
"str r1, [r2] \t\n"
);

byte param01 = *((volatile byte*)(ObjectAddress + 0x08));

bool isRed = ((param01 & 0x0F) == 0x01);

int textureID, paletteID;
textureID = paletteID = (isRed) ? 1 : 0;

int nMaterials = *((volatile int*)(BMDAddress + 0x24));
unsigned int offMaterials = *((volatile unsigned int*)(BMDAddress + 0x28));

unsigned int adrMaterial = offMaterials;
for (int i = 0; i < nMaterials; i++)
{
*((volatile int*)(adrMaterial + 0x04)) = textureID;
*((volatile int*)(adrMaterial + 0x08)) = paletteID;
adrMaterial += 48;
}
}

...
<library_images>
<image id="img_1" name="img_1">
<init_from>img_1.png</init_from>
</image>
<image id="img_2" name="img_2">
<init_from>img_2.png</init_from>
</image>
<image id="img_3" name="img_3">
<init_from>img_3.png</init_from>
</image>
</library_images>
...
<library_effects>
<effect id="mat_1-effect">
<profile_COMMON>
<newparam sid="img_1-surface">
<surface type="2D">
<init_from>img_1</init_from>
</surface>
</newparam>
<newparam sid="img_1-sampler">
<sampler2D>
<source>img_1-surface</source>
</sampler2D>
</newparam>
<technique sid="common">
<phong>
<diffuse>
<texture texture="img_1-sampler" texcoord="UVMap"/>
</diffuse>
</phong>
</technique>
</profile_COMMON>
</effect>
...
</library_effects>
...
<library_materials>
<material id="mat_1" name="mat_1">
<instance_effect url="#mat_1-effect"/>
</material>
</library_materials>
...