Broken breadcrumb background color

[octref]

Issue Type: Bug

Don't know if this is intended, but if so at least we should fix the color for included themes.

VS Code version: Code - Insiders 1.27.0-insider (b00ab52, 2018-08-16T09:29:15.226Z)
OS version: Darwin x64 17.7.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz (8 x 2200)
GPU Status	2d_canvas: enabled checker_imaging: disabled_off flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: enabled rasterization: enabled video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled
Load (avg)	2, 2, 2
Memory (System)	16.00GB (2.63GB free)
Process Argv	/Applications/Visual Studio Code - Insiders.app/Contents/MacOS/Electron -psn_0_7927695
Screen Reader	no
VM	0%

Extensions (16)

Extension	Author (truncated)	Version
markdown-emoji	bie	0.0.7
markdown-preview-github-styles	bie	0.1.2
tslint	eg2	1.0.34
vsc-material-theme	Equ	2.3.0
prettier-vscode	esb	1.6.1
beautify	Hoo	1.3.2
theme-monokai-pro-vscode	mon	1.1.8
vscode-language-pack-ja	MS-	1.26.3
debugger-for-chrome	msj	4.8.2
vetur	oct	0.12.6
polacode	pnp	0.2.2
vscode-sort-json	ric	1.13.0
vue-vscode-snippets	sdr	1.3.0
vscode-csstree	sme	0.7.0
language-stylus	sys	1.9.2
vim	vsc	0.16.0

(2 theme extensions excluded)

[jrieken]

The color can now be themed but it seems like a regression with Insiders...