Class to parse SVG paint values. Do not call this class directly,
it will be removed when browser provide good native support for it.
Following is the BNF grammar of the expression supported.
paint ::= none
| currentColor
| color [icccolor]
| funciri [ none | currentColor | color [icccolor] ]
| inherit
color ::= "#" hexdigit hexdigit hexdigit (hexdigit hexdigit hexdigit)?
| "rgb(" wsp* integer comma integer comma integer wsp* ")"
| "rgb(" wsp* integer "%" comma integer "%" comma integer "%" wsp* ")"
| color-keyword
hexdigit ::= [0-9A-Fa-f]
comma ::= wsp* "," wsp*
icccolor ::= "icc-color(" name (comma-wsp number)+ ")"
name ::= [^,()#x20#x9#xD#xA]*