srt.tmLanguage

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>fileTypes</key>
	<array>
		<string>srt</string>
	</array>
	<key>name</key>
	<string>SRT</string>
	<key>patterns</key>
	<array>
		<dict>
			<key>match</key>
			<string>^(\d+)$</string>
			<key>name</key>
			<string>constant.numeric</string>
		</dict>



		<dict>
			<key>match</key>
			<string>^(\d{2}:\d{2}:\d{2},\d{3}) (-->) (\d{2}:\d{2}:\d{2},\d{3})$</string>

			<key>captures</key>
			<dict>
				<key>1</key>
				<dict>
					<key>name</key>
					<string>variable.parameter</string>
				</dict>
				<key>2</key>
				<dict>
					<key>name</key>
					<string>keyword.control</string>
				</dict>
				<key>3</key>
				<dict>
					<key>name</key>
					<string>variable.parameter</string>
				</dict>
			</dict>

		</dict>

		<dict>
			<key>begin</key>
			<string>(&lt;/?)((?i:b|i|u)\b)</string>
			<key>beginCaptures</key>
			<dict>
				<key>1</key>
				<dict>
					<key>name</key>
					<string>punctuation.definition.tag.begin.html</string>
				</dict>
				<key>2</key>
				<dict>
					<key>name</key>
					<string>entity.name.tag.inline.any.html</string>
				</dict>
			</dict>
			<key>end</key>
			<string>((?: ?/)?&gt;)</string>
			<key>endCaptures</key>
			<dict>
				<key>1</key>
				<dict>
					<key>name</key>
					<string>punctuation.definition.tag.end.html</string>
				</dict>
			</dict>

		</dict>

	</array>

	<key>scopeName</key>
	<string>text.srt</string>
</dict>
</plist>

Nice work.