Shape fill colors for .json theme template don't work

Dear Microsoft,

I've developed a full .json theme template that I'd like to use for my various customers and to help reduce report development time. A lot of reports we create use shapes to create headers and footers. I've been testing in a seperate report and here's the .json code that I'm currently using for shapes:

{
	"name": "Shapetest template",
	"dataColors": [
		"#cc0000",
		"#1c2c44",
		"#c7d6c3",
		"#c0dce6",
		"#f9e984",
		"#264691",
		"#849c9c",
		"#50677a",
		"#334c61",
		"#6e7983",
		"#454b5a",
		"#f9f9f7",
		"#6a7883",
		"#88a0c2",
		"#dd0000",
		"#929292",
		"#ffffff",
		"#252423",
		"#FDAB89",
		"#B687AC",
		"#28738A",
		"#A78F8F",
		"#168980",
		"#293537",
		"#BB4A4A",
		"#B59525",
		"#475052",
		"#6A9FB0",
		"#BD7150",
		"#7B4F71",
		"#1B4D5C",
		"#706060",
		"#0F5C55"
	],
	"visualStyles": {
		"shape": {
			"*": {
				"visualHeader": [
					{
						"show": false
					}
				],
				"background": [
					{
						"color": {
							"solid": {
								"color": "#FFFFFF"
							}
						},
						"transparency": 100
					}
				],
				"fill": [
					{
						"show": true,
						"fillColor": { "solid": { "color": "#FFFFFF"}},
						"transparency": 100
					}
				]
			}
		}
	}
}

I've noticed that the background and visual header properties are setting properly but the fill properties don't seem to work. I got the properties by opening the .pbix file as a .zip and opening the layout file in a code editor:

"sections": [
		{
			"id": 0,
			"name": "ReportSection",
			"displayName": "Page 1",
			"filters": "[]",
			"ordinal": 0,
			"visualContainers": [
				{
					"x": 229.1707317073171,
					"y": 157.1707317073171,
					"z": 1,
					"width": 300.2926829268293,
					"height": 299.4146341463415,
					"config": "{\"name\":\"02976ed171563d9e2075\",\"layouts\":[{\"id\":0,\"position\":{\"x\":229.1707317073171,\"y\":157.1707317073171,\"z\":1,\"width\":300.2926829268293,\"height\":299.4146341463415}}],\"singleVisual\":{\"visualType\":\"shape\",\"drillFilterOtherVisuals\":true,\"objects\":{\"shape\":[{\"properties\":{\"tileShape\":{\"expr\":{\"Literal\":{\"Value\":\"'oval'\"}}}}}],\"rotation\":[{\"properties\":{\"shapeAngle\":{\"expr\":{\"Literal\":{\"Value\":\"0L\"}}}}}],\"fill\":[{\"properties\":{\"fillColor\":{\"solid\":{\"color\":{\"expr\":{\"ThemeDataColor\":{\"ColorId\":3,\"Percent\":0}}}}},\"transparency\":{\"expr\":{\"Literal\":{\"Value\":\"31D\"}}}},\"selector\":{\"id\":\"default\"}}],\"outline\":[{\"properties\":{\"lineColor\":{\"solid\":{\"color\":{\"expr\":{\"ThemeDataColor\":{\"ColorId\":5,\"Percent\":0}}}}},\"weight\":{\"expr\":{\"Literal\":{\"Value\":\"5D\"}}},\"transparency\":{\"expr\":{\"Literal\":{\"Value\":\"12D\"}}}},\"selector\":{\"id\":\"default\"}}]}}}",
					"filters": "[]"
				},

From what I can tell I'm using the right properties but the color isn't being picked up from the .json template file.