diff --git a/lib/prawn-svg.rb b/lib/prawn-svg.rb
index 69cbcbd..ed120d7 100644
--- a/lib/prawn-svg.rb
+++ b/lib/prawn-svg.rb
@@ -26,6 +26,7 @@
 require 'prawn/svg/css/font_family_parser'
 require 'prawn/svg/css/selector_parser'
 require 'prawn/svg/css/stylesheets'
+require 'prawn/svg/css/values_parser'
 require 'prawn/svg/ttf'
 require 'prawn/svg/font'
 require 'prawn/svg/gradients'
diff --git a/lib/prawn/svg/color.rb b/lib/prawn/svg/color.rb
index c467bf1..bf76aa9 100644
--- a/lib/prawn/svg/color.rb
+++ b/lib/prawn/svg/color.rb
@@ -2,7 +2,7 @@ class Prawn::SVG::Color
   RGB = Struct.new(:value)
   CMYK = Struct.new(:value)
 
-  RGB_DEFAULT_COLOR = RGB.new("000000")
+  RGB_DEFAULT_COLOR = RGB.new('000000')
   CMYK_DEFAULT_COLOR = CMYK.new([0, 0, 0, 100])
 
   HTML_COLORS = {
@@ -155,90 +155,91 @@ class Prawn::SVG::Color
     'yellowgreen' => '9acd32'
   }.freeze
 
-  VALUE_REGEXP = "\s*(-?[0-9.]+%?)\s*"
-  RGB_REGEXP = /\Argb\(#{VALUE_REGEXP},#{VALUE_REGEXP},#{VALUE_REGEXP}\)\z/i
-  CMYK_REGEXP = /\Adevice-cmyk\(#{VALUE_REGEXP},#{VALUE_REGEXP},#{VALUE_REGEXP},#{VALUE_REGEXP}\)\z/i
-  URL_REGEXP = /\Aurl\(([^)]*)\)\z/i
+  class << self
+    def parse(color_string, gradients = nil, color_mode = :rgb)
+      url_specified = false
 
-  def self.parse(color_string, gradients = nil, color_mode = :rgb)
-    url_specified = false
+      values = ::Prawn::SVG::CSS::ValuesParser.parse(color_string)
 
-    components = color_string.to_s.strip.scan(/([^(\s]+(\([^)]*\))?)/)
+      result = values.map do |value|
+        case value
+        in ['rgb', args]
+          hex = (0..2).collect do |n|
+            number = args[n].to_f
+            number *= 2.55 if args[n][-1..] == '%'
+            format('%02x', clamp(number.round, 0, 255))
+          end.join
 
-    result = components.map do |color, *_|
-      if m = color.match(/\A#([0-9a-f])([0-9a-f])([0-9a-f])\z/i)
-        RGB.new("#{m[1] * 2}#{m[2] * 2}#{m[3] * 2}")
+          RGB.new(hex)
 
-      elsif color.match(/\A#[0-9a-f]{6}\z/i)
-        RGB.new(color[1..6])
+        in ['device-cmyk', args]
+          cmyk = (0..3).collect do |n|
+            number = args[n].to_f
+            number *= 100 unless args[n][-1..] == '%'
+            clamp(number, 0, 100)
+          end
 
-      elsif hex = HTML_COLORS[color.downcase]
-        hex_color(hex, color_mode)
+          CMYK.new(cmyk)
 
-      elsif m = color.match(RGB_REGEXP)
-        hex = (1..3).collect do |n|
-          value = m[n].to_f
-          value *= 2.55 if m[n][-1..-1] == '%'
-          "%02x" % clamp(value.round, 0, 255)
-        end.join
+        in ['url', [url]]
+          url_specified = true
+          if url[0] == '#' && gradients && (gradient = gradients[url[1..]])
+            gradient
+          end
 
-        RGB.new(hex)
+        in /\A#([0-9a-f])([0-9a-f])([0-9a-f])\z/i
+          RGB.new("#{$1 * 2}#{$2 * 2}#{$3 * 2}")
 
-      elsif m = color.match(CMYK_REGEXP)
-        cmyk = (1..4).collect do |n|
-          value = m[n].to_f
-          value *= 100 unless m[n][-1..-1] == '%'
-          clamp(value, 0, 100)
-        end
+        in /\A#[0-9a-f]{6}\z/i
+          RGB.new(value[1..])
 
-        CMYK.new(cmyk)
+        in String => color
+          if (hex = HTML_COLORS[color.downcase])
+            hex_color(hex, color_mode)
+          end
 
-      elsif matches = color.match(URL_REGEXP)
-        url_specified = true
-        url = matches[1]
-        if url[0] == "#" && gradients && gradient = gradients[url[1..-1]]
-          gradient
+        else
+          nil
         end
       end
-    end
 
-    # Generally, we default to black if the colour was unparseable.
-    # http://www.w3.org/TR/SVG/painting.html section 11.2 says if a URL was
-    # supplied without a fallback, that's an error.
-    result << default_color(color_mode) unless url_specified
+      # Generally, we default to black if the colour was unparseable.
+      # http://www.w3.org/TR/SVG/painting.html section 11.2 says if a URL was
+      # supplied without a fallback, that's an error.
+      result << default_color(color_mode) unless url_specified
 
-    result.compact
-  end
+      result.compact
+    end
 
-  def self.css_color_to_prawn_color(color)
-    result = parse(color).detect {|result| result.is_a?(RGB) || result.is_a?(CMYK)}
-    result.value if result
-  end
+    def css_color_to_prawn_color(color)
+      parse(color).detect { |value| value.is_a?(RGB) || value.is_a?(CMYK) }&.value
+    end
 
-  protected
+    def default_color(color_mode)
+      color_mode == :cmyk ? CMYK_DEFAULT_COLOR : RGB_DEFAULT_COLOR
+    end
 
-  def self.clamp(value, min_value, max_value)
-    [[value, min_value].max, max_value].min
-  end
+    private
 
-  def self.default_color(color_mode)
-    color_mode == :cmyk ? CMYK_DEFAULT_COLOR : RGB_DEFAULT_COLOR
-  end
+    def clamp(value, min_value, max_value)
+      [[value, min_value].max, max_value].min
+    end
 
-  def self.hex_color(hex, color_mode)
-    if color_mode == :cmyk
-      r, g, b = [hex[0..1], hex[2..3], hex[4..5]].map { |h| h.to_i(16) / 255.0 }
-      k = 1 - [r, g, b].max
-      if k == 1
-        CMYK.new([0, 0, 0, 100])
+    def hex_color(hex, color_mode)
+      if color_mode == :cmyk
+        r, g, b = [hex[0..1], hex[2..3], hex[4..5]].map { |h| h.to_i(16) / 255.0 }
+        k = 1 - [r, g, b].max
+        if k == 1
+          CMYK.new([0, 0, 0, 100])
+        else
+          c = (1 - r - k) / (1 - k)
+          m = (1 - g - k) / (1 - k)
+          y = (1 - b - k) / (1 - k)
+          CMYK.new([c, m, y, k].map { |v| (v * 100).round })
+        end
       else
-        c = (1 - r - k) / (1 - k)
-        m = (1 - g - k) / (1 - k)
-        y = (1 - b - k) / (1 - k)
-        CMYK.new([c, m, y, k].map { |v| (v * 100).round })
+        RGB.new(hex)
       end
-    else
-      RGB.new(hex)
     end
   end
 end
diff --git a/lib/prawn/svg/css/values_parser.rb b/lib/prawn/svg/css/values_parser.rb
new file mode 100644
index 0000000..1778531
--- /dev/null
+++ b/lib/prawn/svg/css/values_parser.rb
@@ -0,0 +1,68 @@
+module Prawn::SVG::CSS
+  class ValuesParser
+    class << self
+      def parse(values)
+        result = []
+
+        while values
+          value, remainder = parse_next(values)
+          break unless value
+
+          result << value
+          values = remainder
+        end
+
+        result
+      end
+
+      private
+
+      def parse_next(values)
+        values = values.strip
+        return if values.empty?
+
+        if (matches = values.match(/\A([a-z-]+)\(\s*(.+)/i))
+          parse_function_call(matches[1].downcase, matches[2])
+        else
+          values.split(/\s+/, 2)
+        end
+      end
+
+      # Note this does not support space-separated arguments.
+      # I don't think CSS 2 has any, but in case it does here is the place to add them.
+      def parse_function_call(name, rest)
+        arguments = []
+        in_quote = nil
+        in_escape = false
+        current = ''
+
+        rest.chars.each.with_index do |char, index|
+          if in_escape
+            current << char
+            in_escape = false
+          elsif %w[" '].include?(char)
+            if in_quote == char
+              in_quote = nil
+            elsif in_quote.nil?
+              in_quote = char
+            else
+              current << char
+            end
+          elsif char == '\\'
+            in_escape = true
+          elsif in_quote.nil? && char == ','
+            arguments << current.strip
+            current = ''
+          elsif in_quote.nil? && char == ')'
+            arguments << current.strip
+            return [[name, arguments], rest[index + 1..]]
+          else
+            current << char
+          end
+        end
+
+        [rest, nil]
+      end
+    end
+  end
+end
diff --git a/lib/prawn/svg/elements/base.rb b/lib/prawn/svg/elements/base.rb
index f5a1004..a2c91f8 100644
--- a/lib/prawn/svg/elements/base.rb
+++ b/lib/prawn/svg/elements/base.rb
@@ -261,10 +261,16 @@ def require_positive_value(*args)
     end
   end
 
-  def extract_element_from_url_id_reference(value, expected_type = nil)
-    matches = value.strip.match(/\Aurl\(\s*#(\S+)\s*\)\z/i) if value
-    element = document.elements_by_id[matches[1]] if matches
-    element if element && (expected_type.nil? || element.name == expected_type)
+  def extract_element_from_url_id_reference(values, expected_type = nil)
+    Prawn::SVG::CSS::ValuesParser.parse(values).detect do |value|
+      case value
+      in ['url', [url]]
+        element = document.elements_by_id[url[1..]] if url.start_with?('#')
+        break element if element && (expected_type.nil? || element.name == expected_type)
+      else
+        nil
+      end
+    end
   end
 
   def href_attribute
diff --git a/spec/prawn/svg/css/values_parser_spec.rb b/spec/prawn/svg/css/values_parser_spec.rb
new file mode 100644
index 0000000..d594308
--- /dev/null
+++ b/spec/prawn/svg/css/values_parser_spec.rb
@@ -0,0 +1,16 @@
+require 'spec_helper'
+
+RSpec.describe Prawn::SVG::CSS::ValuesParser do
+  it 'parses specified values' do
+    values = 'hello world url("#myid") no-quote(very good) escaping(")\\")ok") rgb( 1,4,  5 )'
+
+    expect(described_class.parse(values)).to eq [
+      'hello',
+      'world',
+      ['url', ['#myid']],
+      ['no-quote', ['very good']],
+      ['escaping', [')")ok']],
+      ['rgb', %w[1 4 5]]
+    ]
+  end
+end