I was too curious and tried this myself now. It works. The screenshot is from a VirtualBox VM with EFI support enabled.Anyway please post a screenshot/photo if you try this and it actually works
static const struct {
unsigned char r; /* Red percentage value. */
unsigned char g; /* Green percentage value. */
unsigned char b; /* Blue percentage value. */
} color_def[16] = {
{25, 25, 25}, /* black */
{87, 0, 0}, /* dark red */
{38, 71, 54}, /* dark green */
{87, 68, 56}, /* dark yellow */
{44, 50, 56}, /* dark blue */
{86, 55, 76}, /* dark magenta */
{55, 82, 83}, /* dark cyan */
{86, 86, 80}, /* light gray */
{44, 56, 50}, /* dark gray */
{86, 64, 64}, /* light red */
{76, 75, 62}, /* light green */
{94, 87, 68}, /* light yellow */
{58, 75, 95}, /* light blue */
{93, 58, 83}, /* light magenta */
{58, 88, 89}, /* light cyan */
{100, 100, 100}, /* white */
};
static const struct {
unsigned char r; /* Red percentage value. */
unsigned char g; /* Green percentage value. */
unsigned char b; /* Blue percentage value. */
} color_def[16] = {
{2,21,25},
{86,19,18},
{52,60,0},
{70,53,0},
{14,54,82},
{82,21,50},
{16,63,59},
{39,48,51},
{0,16,21},
{79,29,8},
{34,43,45},
{39,48,51},
{51,58,58},
{42,44,76},
{57,63,63},
{99,96,89},
};
# black
kern.vt.color.0.rgb="#3a3a3a"
# dark red
kern.vt.color.1.rgb="#e89393"
# dark green
kern.vt.color.2.rgb="#688060"
# dark yellow
kern.vt.color.3.rgb="#f0dfaf"
# dark blue
kern.vt.color.4.rgb="#93b3a3"
# dark magenta
kern.vt.color.5.rgb="#bca3a3"
# dark cyan
kern.vt.color.6.rgb="#93b3a3"
# light gray
kern.vt.color.7.rgb="#cccccc"
# dark gray
kern.vt.color.8.rgb="#222222"
# light red
kern.vt.color.9.rgb="#dca3a3"
# light green
kern.vt.color.10.rgb="#7f9f7f"
# light yellow
kern.vt.color.11.rgb="#efef8f"
# light blue
kern.vt.color.12.rgb="#8cd0d3"
# light magenta
kern.vt.color.13.rgb="#c0bed1"
# light cyan
kern.vt.color.14.rgb="#8cd0d3"
# white
kern.vt.color.15.rgb="#ffffff"
kern.vty=vt
i915kms_load="YES"
fuse_load="YES"
# brightness control
acpi_video_load="YES"
# Solarized Dark
kern.vt.color.0.rgb="#002831"
kern.vt.color.1.rgb="#d11c24"
kern.vt.color.2.rgb="#738a05"
kern.vt.color.3.rgb="#a57706"
kern.vt.color.4.rgb="#2176c7"
kern.vt.color.5.rgb="#c61c6f"
kern.vt.color.6.rgb="#259286"
kern.vt.color.7.rgb="#708284"
kern.vt.color.8.rgb="#001e27"
kern.vt.color.9.rgb="#bd3613"
kern.vt.color.10.rgb="#475b62"
kern.vt.color.11.rgb="#536870"
kern.vt.color.12.rgb="#708284"
kern.vt.color.13.rgb="#5956ba"
kern.vt.color.14.rgb="#819090"
kern.vt.color.15.rgb="#fcf4dc"