You've got a too old version, update to the current one and you will see something like:

    [:~/code/colout/colout] parse_r+* ± colout -r x
    Available resources:
    STYLES: reverse, bold, italic, normal, conceal, rapid_blink, faint, underline, blink
    COLORS: blue, none, black, yellow, cyan, green, magenta, white, red
    SPECIAL: random, Random, scale, Scale, colormap
    THEMES: g++, cmake, json, perm
    COLORMAPS: rainbow, jet72, Spectrum, spectrum, Rainbow
    LEXERS: Cucumber, abap, ada, ahk, antlr, antlr-as, antlr-cpp, antlr-csharp, antlr-java, antlr-objc, antlr-perl, antlr-python, antlr-ruby, apacheconf, applescript, as, as3, aspx-cs, aspx-vb, asy, basemake, bash, bat, bbcode, befunge, blitzmax, boo, brainfuck, c, c-objdump, cfm, cfs, cheetah, clojure, cmake, coffee-script, common-lisp, console, control, cpp, cpp-objdump, csharp, css, css+django, css+erb, css+genshitext, css+mako, css+myghty, css+php, css+smarty, cython, d, d-objdump, delphi, diff, django, dpatch, duel, dylan, erb, erl, erlang, evoque, factor, felix, fortran, gas, genshi, genshitext, glsl, gnuplot, go, gooddata-cl, groff, haml, haskell, html, html+cheetah, html+django, html+evoque, html+genshi, html+mako, html+myghty, html+php, html+smarty, html+velocity, hx, hybris, ini, io, ioke, irc, jade, java, js, js+cheetah, js+django, js+erb, js+genshitext, js+mako, js+myghty, js+php, js+smarty, jsp, lhs, lighty, llvm, logtalk, lua, make, mako, maql, mason, matlab, matlabsession, minid, modelica, modula2, moocode, mupad, mxml, myghty, mysql, nasm, newspeak, nginx, numpy, objdump, objective-c, objective-j, ocaml, ooc, perl, php, postscript, pot, pov, prolog, properties, protobuf, py3tb, pycon, pytb, python, python3, ragel, ragel-c, ragel-cpp, ragel-d, ragel-em, ragel-java, ragel-objc, ragel-ruby, raw, rb, rbcon, rconsole, rebol, redcode, rhtml, rst, sass, scala, scaml, scheme, scss, smalltalk, smarty, sourceslist, splus, sql, sqlite3, squidconf, ssp, tcl, tcsh, tex, text, trac-wiki, v, vala, vb.net, velocity, vim, xml, xml+cheetah, xml+django, xml+erb, xml+evoque, xml+mako, xml+myghty, xml+php, xml+smarty, xml+velocity, xquery, xslt, yaml