Converting built-in theme of GNOME Terminal for urxvt

Recently I’ve been working on a tool that generates simple reports with ANSI escape codes (mainly with color-related SGR parameters), and I noticed that current color theme of my terminal emulator is too pale to work comfortably, so I decided it’s a good time to change theme to more contrast one—Tango, one of built-in color themes of GNOME Terminal 3.6.2.

Color values for built-in color theme can be obtained from two paths:

1. ~/.gconf/apps/gnome-terminal/profiles/Profile0/%gconf.xml (config)
2. gnome-terminal-3.6.2/src/terminal-profile.c (source code)

First approach (with %gconf.xml) involves taking contents of stringvalue element (which is child of entry element with name="palette" attribute), splitting it by colon, converting values like #EEEEEEEEECEC to ones urxvt understands. This requires one to have GNOME Terminal installed somewhere to select color theme and get config file. As I don’t have that terminal emulator installed (because I don’t use it), I chose second approach (taking values from source code).

First I downloaded, verified (against SHA-256 checksum) and extracted gnome-terminal-3.6.2.tar.xz: that resulted in gnome-terminal-3.6.2/ directory. Quick search revealed that there is terminal_palettes array of arrays of GdkColor on line 202 of gnome-terminal-3.6.2/src/terminal-profile.c. Here’s Tango palette:

{ 0, 0x0000, 0x0000, 0x0000 },
{ 0, 0xcccc, 0x0000, 0x0000 },
{ 0, 0x4e4e, 0x9a9a, 0x0606 },
{ 0, 0xc4c4, 0xa0a0, 0x0000 },
{ 0, 0x3434, 0x6565, 0xa4a4 },
{ 0, 0x7575, 0x5050, 0x7b7b },
{ 0, 0x0606, 0x9820, 0x9a9a },
{ 0, 0xd3d3, 0xd7d7, 0xcfcf },
{ 0, 0x5555, 0x5757, 0x5353 },
{ 0, 0xefef, 0x2929, 0x2929 },
{ 0, 0x8a8a, 0xe2e2, 0x3434 },
{ 0, 0xfcfc, 0xe9e9, 0x4f4f },
{ 0, 0x7272, 0x9f9f, 0xcfcf },
{ 0, 0xadad, 0x7f7f, 0xa8a8 },
{ 0, 0x3434, 0xe2e2, 0xe2e2 },
{ 0, 0xeeee, 0xeeee, 0xecec }

For purposes of GNOME Terminal these “triples” are converted to #rrrrggggbbbb via following (pango-1.39.0/pango/pango-color.c):

g_strdup_printf ("#%04x%04x%04x", color->red, color->green, color->blue);

According to urxvt manual (man urxvt), it allows user to specify colors as rgba:rrrr/gggg/bbbb/aaaa (this is what lines like { 0, 0x0000, 0x0000, 0x0000 } must be converted into):

For complete control, rxvt-unicode also supports "rgba:rrrr/gggg/bbbb/aaaa" (exactly four hex digits/component) colour specifications, where the additional "aaaa" component specifies opacity (alpha) values. The minimum value of 0000 is completely transparent, while "ffff" is completely opaque).

So I wrote simple Python 3 script:

PALETTE_SOURCE = """
{ 0, 0x0000, 0x0000, 0x0000 },
{ 0, 0xcccc, 0x0000, 0x0000 },
{ 0, 0x4e4e, 0x9a9a, 0x0606 },
{ 0, 0xc4c4, 0xa0a0, 0x0000 },
{ 0, 0x3434, 0x6565, 0xa4a4 },
{ 0, 0x7575, 0x5050, 0x7b7b },
{ 0, 0x0606, 0x9820, 0x9a9a },
{ 0, 0xd3d3, 0xd7d7, 0xcfcf },
{ 0, 0x5555, 0x5757, 0x5353 },
{ 0, 0xefef, 0x2929, 0x2929 },
{ 0, 0x8a8a, 0xe2e2, 0x3434 },
{ 0, 0xfcfc, 0xe9e9, 0x4f4f },
{ 0, 0x7272, 0x9f9f, 0xcfcf },
{ 0, 0xadad, 0x7f7f, 0xa8a8 },
{ 0, 0x3434, 0xe2e2, 0xe2e2 },
{ 0, 0xeeee, 0xeeee, 0xecec }
""".strip()
OUTPUT_TEMPLATE = "urxvt*color{:d}: rgba:{:04x}/{:04x}/{:04x}/ffff"


for n, palette_line in enumerate(PALETTE_SOURCE.split(",\n")):
    line = palette_line.replace("{ 0, ", "").replace(" }", "")
    triple = [int(s, base=16) for s in line.split(", ")]
    print(OUTPUT_TEMPLATE.format(n, *triple))

Here’s the output (can be pasted into .Xdefaults):

urxvt*color0: rgba:0000/0000/0000/ffff
urxvt*color1: rgba:cccc/0000/0000/ffff
urxvt*color2: rgba:4e4e/9a9a/0606/ffff
urxvt*color3: rgba:c4c4/a0a0/0000/ffff
urxvt*color4: rgba:3434/6565/a4a4/ffff
urxvt*color5: rgba:7575/5050/7b7b/ffff
urxvt*color6: rgba:0606/9820/9a9a/ffff
urxvt*color7: rgba:d3d3/d7d7/cfcf/ffff
urxvt*color8: rgba:5555/5757/5353/ffff
urxvt*color9: rgba:efef/2929/2929/ffff
urxvt*color10: rgba:8a8a/e2e2/3434/ffff
urxvt*color11: rgba:fcfc/e9e9/4f4f/ffff
urxvt*color12: rgba:7272/9f9f/cfcf/ffff
urxvt*color13: rgba:adad/7f7f/a8a8/ffff
urxvt*color14: rgba:3434/e2e2/e2e2/ffff
urxvt*color15: rgba:eeee/eeee/ecec/ffff