diff --git a/autoload/rainbow.vim b/autoload/rainbow.vim
index d71f0fc..af024c0 100644
--- a/autoload/rainbow.vim
+++ b/autoload/rainbow.vim
@@ -28,9 +28,9 @@ fun s:resolve_parenthesis_with(init_state, p)
 		elseif k == 'contained'
 			let contained = 1
 		elseif k == 'kind'
-			let kind = v
+			let kind = s:trim(v)
 		elseif k == 'upkind'
-			let upkind = v
+			let upkind = s:trim(v)
 		else
 			let paren .= s
 		endif
@@ -62,17 +62,14 @@ fun rainbow#syn(config)
 	let kindlist = {}
 	for id in range(len(conf.parentheses))
 		let [paren, contained, containedin, contains_prefix, contains, op, kind, upkind] = s:resolve_parenthesis_with(glob_paran_opts, conf.parentheses[id])
-		let kind = split(kind, ',')
-		if kind == []
-		   	let kind = ['']
-	   	endif
+		let kind = kind == '' ? [''] : split(kind, ',', 1)->uniq()
+		let upkind = (upkind == '' ? [] : split(upkind, ',', 1))->extend(kind)->uniq()
 		for k in kind
 			if !has_key(kindlist, k)
-			   	let kindlist[k] = []
-		   	endif
+				let kindlist[k] = []
+			endif
 			call add(kindlist[k], id)
 		endfor
-		let upkind = split(upkind, ',', 1)->extend(kind)->uniq()
 		for lv in range(cycle)
 			let uplv = ((lv + cycle - 1) % cycle)
 			let [rid, pid, upid] = [s:synID(prefix, 'r', lv, id), s:synID(prefix, 'p', lv, id), upkind->mapnew('"@".s:synGroupID(prefix, "Regions", uplv, v:val)')->join(',')]
diff --git a/autoload/rainbow_main.vim b/autoload/rainbow_main.vim
index dee0d7c..e5d4b8b 100644
--- a/autoload/rainbow_main.vim
+++ b/autoload/rainbow_main.vim
@@ -45,11 +45,13 @@ let s:rainbow_conf = {
 \			'parentheses': ['start=/(/ end=/)/', 'start=/{/ end=/}/', 'start=/\v\[\ze($|!(\=*\[))/ end=/\]/'],
 \		},
 \		'zsh': {
-\			'parentheses': ['start=/((/ end=/))/ kind=arithQuote upkind=,', 'start=/\v\(\ze($|[^(])/ end=/)/',
-\				'start=/(/ end=/)/ contained containedin=zshMathSubst upkind=arithQuote',
-\				'start=/\$\zs((/ end=/))/ contained containedin=zshMathSubst upkind=arithQuote',
+\			'parentheses': [
+\				'start=/\v\(\ze($|[^(])/ end=/)/',
+\				'start=/((/ end=/))/ kind=arithQuote upkind=,',
+\				'start=/\$((/ end=/))/ kind=arithQuote upkind=,arithInner',
+\				'start=/(/ end=/)/ contained kind=arithInner upkind=arithQuote',
 \				'start=/\V[[/ end=/]]/', 'start=/\v\[\ze($|[^[])/ end=/]/',
-\				'start=/{/ end=/}/']
+\				'start=/{/ end=/}/'],
 \		},
 \		'perl': {
 \			'syn_name_prefix': 'perlBlockFoldRainbow',
diff --git a/tests/test.zsh b/tests/test.zsh
new file mode 100644
index 0000000..5760c9e
--- /dev/null
+++ b/tests/test.zsh
@@ -0,0 +1,6 @@
+(((($(((1+(2+3))))+4*5)*6)))
+[[ $((1 + 2)) == $([ ] || echo 3) ]]
+
+function f() {
+}
+