nodejs optimizer for html/css string/hex/rgba color code golf

color-golf.js

#!/usr/bin/env node
const F=require('fs'),N=process.argv[2],O=N.replace(/(\.[^.]*)?$/,"-opt$1")
const M={
aliceblue:'#f0f8ff',antiquewhite:'#faebd7',aqua:'#0ff',aquamarine:'#7fffd4',azure:'#f0ffff',beige:'#f5f5dc',bisque:'#ffe4c4',black:'#000',blanchedalmond:'#ffebcd',blue:'#00f',blueviolet:'#8a2be2',brown:'#a52a2a',burlywood:'#deb887',cadetblue:'#5f9ea0',chartreuse:'#7fff00',chocolate:'#d2691e',coral:'#ff7f50',cornflowerblue:'#6495ed',cornsilk:'#fff8dc',crimson:'#dc143c',cyan:'#0ff',darkblue:'#00008b',darkcyan:'#008b8b',darkgoldenrod:'#b8860b',darkgray:'#a9a9a9',darkgreen:'#006400',darkgrey:'#a9a9a9',darkkhaki:'#bdb76b',darkmagenta:'#8b008b',darkolivegreen:'#556b2f',darkorange:'#ff8c00',darkorchid:'#9932cc',darkred:'#8b0000',darksalmon:'#e9967a',darkseagreen:'#8fbc8f',darkslateblue:'#483d8b',darkslategray:'#2f4f4f',darkslategrey:'#2f4f4f',darkturquoise:'#00ced1',darkviolet:'#9400d3',deeppink:'#ff1493',deepskyblue:'#00bfff',dimgray:'#696969',dimgrey:'#696969',dodgerblue:'#1e90ff',firebrick:'#b22222',floralwhite:'#fffaf0',forestgreen:'#228b22',fuchsia:'#f0f',gainsboro:'#dcdcdc',ghostwhite:'#f8f8ff',gold:'#ffd700',goldenrod:'#daa520',gray:'#808080',green:'#008000',greenyellow:'#adff2f',grey:'#808080',honeydew:'#f0fff0',hotpink:'#ff69b4',indianred:'#cd5c5c',indigo:'#4b0082',ivory:'#fffff0',khaki:'#f0e68c',lavender:'#e6e6fa',lavenderblush:'#fff0f5',lawngreen:'#7cfc00',lemonchiffon:'#fffacd',lightblue:'#add8e6',lightcoral:'#f08080',lightcyan:'#e0ffff',lightgoldenrodyellow:'#fafad2',lightgray:'#d3d3d3',lightgreen:'#90ee90',lightgrey:'#d3d3d3',lightpink:'#ffb6c1',lightsalmon:'#ffa07a',lightseagreen:'#20b2aa',lightskyblue:'#87cefa',lightslategray:'#789',lightslategrey:'#789',lightsteelblue:'#b0c4de',lightyellow:'#ffffe0',lime:'#0f0',limegreen:'#32cd32',linen:'#faf0e6',magenta:'#f0f',maroon:'#800000',mediumaquamarine:'#66cdaa',mediumblue:'#0000cd',mediumorchid:'#ba55d3',mediumpurple:'#9370db',mediumseagreen:'#3cb371',mediumslateblue:'#7b68ee',mediumspringgreen:'#00fa9a',mediumturquoise:'#48d1cc',mediumvioletred:'#c71585',midnightblue:'#191970',mintcream:'#f5fffa',mistyrose:'#ffe4e1',moccasin:'#ffe4b5',navajowhite:'#ffdead',navy:'#000080',oldlace:'#fdf5e6',olive:'#808000',olivedrab:'#6b8e23',orange:'#ffa500',orangered:'#ff4500',orchid:'#da70d6',palegoldenrod:'#eee8aa',palegreen:'#98fb98',paleturquoise:'#afeeee',palevioletred:'#db7093',papayawhip:'#ffefd5',peachpuff:'#ffdab9',peru:'#cd853f',pink:'#ffc0cb',plum:'#dda0dd',powderblue:'#b0e0e6',purple:'#800080',rebeccapurple:'#663399',red:'#f00',rosybrown:'#bc8f8f',royalblue:'#4169e1',saddlebrown:'#8b4513',salmon:'#fa8072',sandybrown:'#f4a460',seagreen:'#2e8b57',seashell:'#fff5ee',sienna:'#a0522d',silver:'#c0c0c0',skyblue:'#87ceeb',slateblue:'#6a5acd',slategray:'#708090',slategrey:'#708090',snow:'#fffafa',springgreen:'#00ff7f',steelblue:'#4682b4',tan:'#d2b48c',teal:'#008080',thistle:'#d8bfd8',tomato:'#ff6347',turquoise:'#40e0d0',violet:'#ee82ee',wheat:'#f5deb3',white:'#fff',whitesmoke:'#f5f5f5',yellow:'#ff0',yellowgreen:'#9acd32',transparent:'rgba(0,0,0,0)'
}
const D=F.readFileSync(N,'utf8')
const H=H=>/^#([\da-fA-F])\1([\da-fA-F])\2([\da-fA-F])\3$/.test(H)?'#'+H[1]+H[3]+H[5]:H
const R=(r,g,b)=>'#'+[r,g,b].map(x=>('0'+(+x).toString(16)).slice(-2)).join('')
const Q=([_,r,g,b,a])=>{
 r=+r,g=+g,b=+b,a=a==null?1:+a
 let X=R(r,g,b)
 if(a==1)return H(X)
 let Y=Math.round(a*255).toString(16).padStart(2,'0')
 return X+Y
}
const S=D.replace(
/rgba?\s*\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*,\s*(\d{1,3})(?:\s*,\s*([.0-9]+))?\s*\)/gi,
Q
).replace(
/#[\da-fA-F]{6}\b/g,H
).replace(
/#[\da-fA-F]{3,8}\b/g,H
).replace(
new RegExp('\\b(' + Object.keys(M).join('|') + ')\\b','gi'),
k=>M[k.toLowerCase()]
)
F.writeFileSync(O,S)
console.log(O)