Garmin Edge Change colour of navigation line using map themes

Hi,

I've spent the last few hours going through forums from 5 or so years ago talking about using the Map Themes to change the colour of the magenta navigation line. I have some experience with coding and troubleshooting but alas I cannot seem to change the colour. I have tried all combinations of switching from default themes and restarting the device to no avail. I'm very sure the XML is all good but here it is anyway (the last field is what should actually change the colour).

<?xml version="1.0" encoding="UTF-8"?>
<garmin_map_theme>
	<metadata>
		<title>Classic Red course</title>
		<description>Red navigation line</description>
        <category>0</category>
	</metadata>
	<stylelist>
		<style field="MPM_MDB_TRK_BLACK_CLR">
			<color>
				<primary day="#ff000000" night="#ff000000"/>
				<secondary day="#ff000000" night="#ff000000"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_DK_RED_CLR">
			<color>
				<primary day="#ff880000" night="#ff880000"/>
				<secondary day="#ff880000" night="#ff880000"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_DK_GREEN_CLR">
			<color>
				<primary day="#ff008000" night="#ff008000"/>
				<secondary day="#ff008000" night="#ff008000"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_DK_YELLOW_CLR">
			<color>
				<primary day="#ffb07800" night="#ffb07800"/>
				<secondary day="#ffb07800" night="#ffb07800"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_DK_BLUE_CLR">
			<color>
				<primary day="#ff000080" night="#ff000080"/>
				<secondary day="#ff000080" night="#ff000080"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_DK_MAGENTA_CLR">
			<color>
				<primary day="#ff800080" night="#ff800080"/>
				<secondary day="#ff800080" night="#ff800080"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_DK_CYAN_CLR">
			<color>
				<primary day="#ff008080" night="#ff008080"/>
				<secondary day="#ff008080" night="#ff008080"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_LT_GRAY_CLR">
			<color>
				<primary day="#ffc0c0c0" night="#ffc0c0c0"/>
				<secondary day="#ffc0c0c0" night="#ffc0c0c0"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_DK_GRAY_CLR">
			<color>
				<primary day="#ff808080" night="#ff808080"/>
				<secondary day="#ff808080" night="#ff808080"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_RED_CLR">
			<color>
				<primary day="#ffb00000" night="#ffb00000"/>
				<secondary day="#ffb00000" night="#ffb00000"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_GREEN_CLR">
			<color>
				<primary day="#ff00b800" night="#ff00b800"/>
				<secondary day="#ff00b800" night="#ff00b800"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_YELLOW_CLR">
			<color>
				<primary day="#ff989800" night="#ff989800"/>
				<secondary day="#ff989800" night="#ff989800"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_BLUE_CLR">
			<color>
				<primary day="#ff0000f8" night="#ff0000f8"/>
				<secondary day="#ff0000f8" night="#ff0000f8"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_MAGENTA_CLR">
			<color>
				<primary day="#fff800f8" night="#fff800f8"/>
				<secondary day="#fff800f8" night="#fff800f8"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_CYAN_CLR">
			<color>
				<primary day="#ff00fcf8" night="#ff00fcf8"/>
				<secondary day="#ff00fcf8" night="#ff00fcf8"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_WHITE_CLR">
			<color>
				<primary day="#fff8f8f8" night="#fff8f8f8"/>
				<secondary day="#fff8f8f8" night="#fff8f8f8"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_LT_BLUE">
			<color>
				<primary day="#ff20a8e0" night="#ff20a8e0"/>
				<secondary day="#ff20a8e0" night="#ff20a8e0"/>
			</color>
		</style>
		<style field="MPM_MDB_TRK_TRANSPRNT_CLR">
			<color>
				<primary day="#00f8fcf8" night="#00f8fcf8"/>
				<secondary day="#00f8fcf8" night="#00f8fcf8"/>
			</color>
		</style>
		<style field="MPM_POPULARITY_1_CLR">
			<color>
				<primary day="#ffa8a8f8" night="#ffa8a8f8"/>
				<secondary day="#ffa8a8f8" night="#ffa8a8f8"/>
			</color>
		</style>
		<style field="MPM_POPULARITY_2_CLR">
			<color>
				<primary day="#ffa854f8" night="#ffa854f8"/>
				<secondary day="#ffa854f8" night="#ffa854f8"/>
			</color>
		</style>
		<style field="MPM_POPULARITY_3_CLR">
			<color>
				<primary day="#ffa854f8" night="#ffa854f8"/>
				<secondary day="#ffa854f8" night="#ffa854f8"/>
			</color>
		</style>
		<style field="MPM_POPULARITY_4_CLR">
			<color>
				<primary day="#ffa800f8" night="#ffa800f8"/>
				<secondary day="#ffa800f8" night="#ffa800f8"/>
			</color>
		</style>
		<style field="MPM_POPULARITY_5_CLR">
			<color>
				<primary day="#ffa800f8" night="#ffa800f8"/>
				<secondary day="#ffa800f8" night="#ffa800f8"/>
			</color>
		</style>
		<style field="MPM_POPULARITY_6_CLR">
			<color>
				<primary day="#ff500050" night="#ff500050"/>
				<secondary day="#ff500050" night="#ff500050"/>
			</color>
		</style>
		<style field="MPM_POPULARITY_7_CLR">
			<color>
				<primary day="#ff500050" night="#ff500050"/>
				<secondary day="#ff500050" night="#ff500050"/>
			</color>
		</style>
		<style field="MPM_ACTV_CRS_CLR">
			<color>
				<primary day="#ff005ac8" night="#ff005ac8"/>
				<secondary day="#ff024eab" night="#ff024eab"/>
			</color>
		</style>
	</stylelist>
</garmin_map_theme>

I apprectiate nothing in this area has been touched upon for a while but if anyone knows anything it'd be a great help

Best,

Andrew