diff --git a/src/pikchr.ts b/src/pikchr.ts
new file mode 100644
index 0000000..a3dd64e
--- /dev/null
+++ b/src/pikchr.ts
@@ -0,0 +1,150 @@
+
+import { strip_svg } from './svg';
+
+export function post_process_pikchr_svg(svg: string, size?: string) {
+	svg = strip_svg(svg);
+
+	// text
+	for (const [ color, regex ] of Object.entries(text_regex)) {
+		svg = svg.replace(regex, `<text fill="${text_css_vars[color]}"`);
+	}
+
+	// shape fill
+	for (const [ color, regex ] of Object.entries(shape_fill_regex)) {
+		svg = svg.replace(regex, `<path style="fill:${fill_css_vars[color]}`);
+	}
+
+	// arrow heads
+	for (const [ color, regex ] of Object.entries(arrow_head_regex)) {
+		svg = svg.replace(regex, `fill:${line_css_vars[color]}`);
+	}
+
+	// lines / boxes
+	for (const [ color, regex ] of Object.entries(line_regex)) {
+		svg = svg.replace(regex, `stroke:${line_css_vars[color]}`);
+	}
+
+	return svg;
+}
+
+
+
+type CSSVarColor
+	= 'black'
+	| 'red'
+	| 'orange'
+	| 'yellow'
+	| 'green'
+	| 'teal'
+	| 'pink'
+	| 'purple'
+	| 'blue'
+	| 'indigo'
+	| 'magenta'
+	| 'brown'
+	;
+
+const text_regex: Record<CSSVarColor, RegExp> = {
+	black: /\b<text fill="rgb\(0,0,0\)"/gi,
+	red:   /\b<text fill="rgb\(255,0,0\)"/gi,
+	orange: /\b<text fill="rgb\(255,165,0\)"/gi,
+	yellow: /\b<text fill="rgb\(255,255,0\)"/gi,
+	green: /\b<text fill="rgb\(0,128,0\)"/gi,
+	teal: /\b<text fill="rgb\(0,128,128\)"/gi,
+	pink: /\b<text fill="rgb\(255,192,203\)"/gi,
+	purple: /\b<text fill="rgb\(128,0,128\)"/gi,
+	blue: /\b<text fill="rgb\(0,0,255\)"/gi,
+	indigo: /\b<text fill="rgb\(75,0,130\)"/gi,
+	magenta: /\b<text fill="rgb\(255,0,255\)"/gi,
+	brown: /\b<text fill="rgb\(165,42,42\)"/gi,
+};
+
+const line_regex: Record<CSSVarColor, RegExp> = {
+	black: /stroke:rgb\(0,0,0\)/gi,
+	red:   /stroke:rgb\(255,0,0\)/gi,
+	orange: /stroke:rgb\(255,165,0\)/gi,
+	yellow: /stroke:rgb\(255,255,0\)/gi,
+	green: /stroke:rgb\(0,128,0\)/gi,
+	teal: /stroke:rgb\(0,128,128\)/gi,
+	pink: /stroke:rgb\(255,192,203\)/gi,
+	purple: /stroke:rgb\(128,0,128\)/gi,
+	blue: /stroke:rgb\(0,0,255\)/gi,
+	indigo: /stroke:rgb\(75,0,130\)/gi,
+	magenta: /stroke:rgb\(255,0,255\)/gi,
+	brown: /stroke:rgb\(165,42,42\)/gi,
+};
+
+const shape_fill_regex = {
+	black: /\b<path style="fill:rgb\(0,0,0\)/gi,
+	red:   /\b<path style="fill:rgb\(255,0,0\)/gi,
+	orange: /\b<path style="fill:rgb\(255,165,0\)/gi,
+	yellow: /\b<path style="fill:rgb\(255,255,0\)/gi,
+	green: /\b<path style="fill:rgb\(0,128,0\)/gi,
+	teal: /\b<path style="fill:rgb\(0,128,128\)/gi,
+	pink: /\b<path style="fill:rgb\(255,192,203\)/gi,
+	purple: /\b<path style="fill:rgb\(128,0,128\)/gi,
+	blue: /\b<path style="fill:rgb\(0,0,255\)/gi,
+	indigo: /\b<path style="fill:rgb\(75,0,130\)/gi,
+	magenta: /\b<path style="fill:rgb\(255,0,255\)/gi,
+	brown: /\b<path style="fill:rgb\(165,42,42\)/gi,
+}
+
+const arrow_head_regex: Record<CSSVarColor, RegExp> = {
+	black: /fill:rgb\(0,0,0\)/gi,
+	red:   /fill:rgb\(255,0,0\)/gi,
+	orange: /fill:rgb:\(255,165,0\)/gi,
+	yellow: /fill:rgb:\(255,255,0\)/gi,
+	green: /fill:rgb:\(0,128,0\)/gi,
+	teal: /fill:rgb:\(0,128,128\)/gi,
+	pink: /fill:rgb:\(255,192,203\)/gi,
+	purple: /fill:rgb:\(128,0,128\)/gi,
+	blue: /fill:rgb:\(0,0,255\)/gi,
+	indigo: /fill:rgb:\(75,0,130\)/gi,
+	magenta: /fill:rgb:\(255,0,255\)/gi,
+	brown: /fill:rgb:\(165,42,42\)/gi,
+};
+
+const line_css_vars: Record<CSSVarColor, string> = {
+	black: 'var(--theme-line, currentcolor)',
+	red: 'var(--theme-chart-shape-red-line, currentcolor)',
+	orange: 'var(--theme-chart-shape-orange-line, currentcolor)',
+	yellow: 'var(--theme-chart-shape-yellow-line, currentcolor)',
+	green: 'var(--theme-chart-shape-green-line, currentcolor)',
+	teal: 'var(--theme-chart-shape-teal-line, currentcolor)',
+	pink: 'var(--theme-chart-shape-pink-line, currentcolor)',
+	purple: 'var(--theme-chart-shape-purple-line, currentcolor)',
+	blue: 'var(--theme-chart-shape-blue-line, currentcolor)',
+	indigo: 'var(--theme-chart-shape-indigo-line, currentcolor)',
+	magenta: 'var(--theme-chart-shape-magenta-line, currentcolor)',
+	brown: 'var(--theme-chart-shape-brown-line, currentcolor)',
+};
+
+const text_css_vars: Record<CSSVarColor, string> = {
+	black: 'var(--theme-text-body, currentcolor)',
+	red: 'var(--theme-chart-shape-red-line, currentcolor)',
+	orange: 'var(--theme-chart-shape-orange-line, currentcolor)',
+	yellow: 'var(--theme-chart-shape-yellow-line, currentcolor)',
+	green: 'var(--theme-chart-shape-green-line, currentcolor)',
+	teal: 'var(--theme-chart-shape-teal-line, currentcolor)',
+	pink: 'var(--theme-chart-shape-pink-line, currentcolor)',
+	purple: 'var(--theme-chart-shape-purple-line, currentcolor)',
+	blue: 'var(--theme-chart-shape-blue-line, currentcolor)',
+	indigo: 'var(--theme-chart-shape-indigo-line, currentcolor)',
+	magenta: 'var(--theme-chart-shape-magenta-line, currentcolor)',
+	brown: 'var(--theme-chart-shape-brown-line, currentcolor)',
+};
+
+const fill_css_vars: Record<CSSVarColor, string> = {
+	black: 'var(--theme-chart-shape-black-fill, transparent)',
+	red: 'var(--theme-chart-shape-red-fill, transparent)',
+	orange: 'var(--theme-chart-shape-orange-fill, transparent)',
+	yellow: 'var(--theme-chart-shape-yellow-fill, transparent)',
+	green: 'var(--theme-chart-shape-green-fill, transparent)',
+	teal: 'var(--theme-chart-shape-teal-fill, transparent)',
+	pink: 'var(--theme-chart-shape-pink-fill, transparent)',
+	purple: 'var(--theme-chart-shape-purple-fill, transparent)',
+	blue: 'var(--theme-chart-shape-blue-fill, transparent)',
+	indigo: 'var(--theme-chart-shape-indigo-fill, transparent)',
+	magenta: 'var(--theme-chart-shape-magenta-fill, transparent)',
+	brown: 'var(--theme-chart-shape-brown-fill, transparent)',
+};
diff --git a/src/renderer.ts b/src/renderer.ts
index 7e66c69..e26e614 100644
--- a/src/renderer.ts
+++ b/src/renderer.ts
@@ -14,6 +14,7 @@ import { bind_data_async } from './async-steps';
 import { render_vega_spec } from './vega';
 import { parse_attributes } from './attrs';
 import { MarkdownOptions } from './render';
+import { post_process_pikchr_svg } from './pikchr';
 
 export function create_renderer(opts: MarkdownOptions) {
 	const renderer = new marked.Renderer();
@@ -275,23 +276,3 @@ function post_process_nomnoml_svg(svg: string, size?: string) {
 
 	return svg;
 }
-
-const svg_text_fill_rgb_000 = /\b<text fill="rgb\(0,0,0\)"/gi;
-const svg_fill_rgb_000 = /fill:rgb\(0,0,0\)/gi;
-const svg_stroke_rgb_000 = /stroke:rgb\(0,0,0\)/gi;
-
-// todo: css variables
-function post_process_pikchr_svg(svg: string, size?: string) {
-	svg = strip_svg(svg);
-
-	// text
-	svg = svg.replace(svg_text_fill_rgb_000, '<text fill="var(--theme-text-body, currentcolor)"');
-
-	// arrow heads
-	svg = svg.replace(svg_fill_rgb_000, 'fill:var(--theme-line, currentcolor)');
-
-	// lines / boxes
-	svg = svg.replace(svg_stroke_rgb_000, 'stroke:var(--theme-line, currentcolor)');
-
-	return svg;
-}