diff --git a/src/Colour.php b/src/Colour.php
deleted file mode 100644
index 4f158a77..00000000
--- a/src/Colour.php
+++ /dev/null
@@ -1,112 +0,0 @@
-<?php
-define('MSZ_COLOUR_INHERIT', 0x40000000);
-
-function colour_create(): int
-{
-    return 0;
-}
-
-function colour_none(): int
-{
-    return MSZ_COLOUR_INHERIT;
-}
-
-function colour_set_inherit(int &$colour): void
-{
-    $colour |= MSZ_COLOUR_INHERIT;
-}
-
-function colour_unset_inherit(int &$colour): void
-{
-    $colour &= ~MSZ_COLOUR_INHERIT;
-}
-
-function colour_get_inherit(int $colour): bool
-{
-    return ($colour & MSZ_COLOUR_INHERIT) > 0;
-}
-
-function colour_get_red(int $colour): int
-{
-    return ($colour >> 16) & 0xFF;
-}
-
-function colour_set_red(int &$colour, int $red): void
-{
-    $red = $red & 0xFF;
-    $colour &= ~0xFF0000;
-    $colour |= $red << 16;
-}
-
-function colour_get_green(int $colour): int
-{
-    return ($colour >> 8) & 0xFF;
-}
-
-function colour_set_green(int &$colour, int $green): void
-{
-    $green = $green & 0xFF;
-    $colour &= ~0xFF00;
-    $colour |= $green << 8;
-}
-
-function colour_get_blue(int $colour): int
-{
-    return $colour & 0xFF;
-}
-
-function colour_set_blue(int &$colour, int $blue): void
-{
-    $blue = $blue & 0xFF;
-    $colour &= ~0xFF;
-    $colour |= $blue;
-}
-
-function colour_get_hex(int $colour, string $format = '#%s'): string
-{
-    return sprintf(
-        $format,
-        dechex_pad($colour & 0xFFFFFF, 6)
-    );
-}
-
-function colour_get_css(int $colour): string
-{
-    if (colour_get_inherit($colour)) {
-        return 'inherit';
-    }
-
-    return colour_get_hex($colour);
-}
-
-function colour_from_rgb(int &$colour, int $red, int $green, int $blue): bool
-{
-    colour_set_red($colour, $red);
-    colour_set_green($colour, $green);
-    colour_set_blue($colour, $blue);
-    return true;
-}
-
-function colour_from_hex(int &$colour, string $hex): bool
-{
-    if ($hex[0] === '#') {
-        $hex = substr($hex, 1);
-    }
-
-    $length = strlen($hex);
-
-    if ($length === 3) {
-        $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
-    } elseif ($length !== 6) {
-        return false;
-    }
-
-    colour_from_rgb(
-        $colour,
-        hexdec(substr($hex, 0, 2)),
-        hexdec(substr($hex, 2, 2)),
-        hexdec(substr($hex, 4, 2))
-    );
-
-    return true;
-}