diff --git a/doc/coding_standards.rst b/doc/coding_standards.rst
index d10906fa6..46be8eca6 100644
--- a/doc/coding_standards.rst
+++ b/doc/coding_standards.rst
@@ -105,3 +105,9 @@ standards:
              true
          {% endif %}
      {% endblock %}
+
+* Use ``:`` instead of ``=`` to separate argument names and values:
+
+  .. code-block:: twig
+
+     {{ data|convert_encoding(from: 'iso-2022-jp', to: 'UTF-8') }}
diff --git a/doc/filters/data_uri.rst b/doc/filters/data_uri.rst
index 131a71bb8..a68deb0f2 100644
--- a/doc/filters/data_uri.rst
+++ b/doc/filters/data_uri.rst
@@ -11,13 +11,13 @@ The ``data_uri`` filter generates a URL using the data scheme as defined in
     {{ source('path_to_image')|data_uri }}
 
     {# force the mime type, disable the guessing of the mime type #}
-    {{ image_data|data_uri(mime="image/svg") }}
+    {{ image_data|data_uri(mime: "image/svg") }}
 
     {# also works with plain text #}
-    {{ '<b>foobar</b>'|data_uri(mime="text/html") }}
+    {{ '<b>foobar</b>'|data_uri(mime: "text/html") }}
 
     {# add some extra parameters #}
-    {{ '<b>foobar</b>'|data_uri(mime="text/html", parameters={charset: "ascii"}) }}
+    {{ '<b>foobar</b>'|data_uri(mime: "text/html", parameters: {charset: "ascii"}) }}
 
 .. note::
 
diff --git a/doc/filters/format_currency.rst b/doc/filters/format_currency.rst
index 8b649bf5d..c4c364a00 100644
--- a/doc/filters/format_currency.rst
+++ b/doc/filters/format_currency.rst
@@ -45,7 +45,7 @@ By default, the filter uses the current locale. You can pass it explicitly:
 .. code-block:: twig
 
     {# 1.000.000,00 € #}
-    {{ '1000000'|format_currency('EUR', locale='de') }}
+    {{ '1000000'|format_currency('EUR', locale: 'de') }}
 
 .. note::
 
diff --git a/doc/filters/format_datetime.rst b/doc/filters/format_datetime.rst
index 3ca9f0be6..9caf1992c 100644
--- a/doc/filters/format_datetime.rst
+++ b/doc/filters/format_datetime.rst
@@ -16,13 +16,13 @@ You can tweak the output for the date part and the time part:
 .. code-block:: twig
 
     {# 23:39 #}
-    {{ '2019-08-07 23:39:12'|format_datetime('none', 'short', locale='fr') }}
+    {{ '2019-08-07 23:39:12'|format_datetime('none', 'short', locale: 'fr') }}
 
     {# 07/08/2019 #}
-    {{ '2019-08-07 23:39:12'|format_datetime('short', 'none', locale='fr') }}
+    {{ '2019-08-07 23:39:12'|format_datetime('short', 'none', locale: 'fr') }}
 
     {# mercredi 7 août 2019 23:39:12 UTC #}
-    {{ '2019-08-07 23:39:12'|format_datetime('full', 'full', locale='fr') }}
+    {{ '2019-08-07 23:39:12'|format_datetime('full', 'full', locale: 'fr') }}
 
 Supported values are: ``none``, ``short``, ``medium``, ``long``, ``full``,
 ``relative_short``, ``relative_medium``, ``relative_long``, and
@@ -34,7 +34,7 @@ For greater flexibility, you can even define your own pattern
 .. code-block:: twig
 
     {# 11 oclock PM, GMT #}
-    {{ '2019-08-07 23:39:12'|format_datetime(pattern="hh 'oclock' a, zzzz") }}
+    {{ '2019-08-07 23:39:12'|format_datetime(pattern: "hh 'oclock' a, zzzz") }}
 
 Locale
 ------
@@ -44,7 +44,7 @@ By default, the filter uses the current locale. You can pass it explicitly:
 .. code-block:: twig
 
     {# 7 août 2019 23:39:12 #}
-    {{ '2019-08-07 23:39:12'|format_datetime(locale='fr') }}
+    {{ '2019-08-07 23:39:12'|format_datetime(locale: 'fr') }}
 
 Timezone
 --------
@@ -55,14 +55,14 @@ it by explicitly specifying a timezone:
 
 .. code-block:: twig
 
-    {{ datetime|format_datetime(locale='en', timezone='Pacific/Midway') }}
+    {{ datetime|format_datetime(locale: 'en', timezone: 'Pacific/Midway') }}
 
 If the date is already a DateTime object, and if you want to keep its current
 timezone, pass ``false`` as the timezone value:
 
 .. code-block:: twig
 
-    {{ datetime|format_datetime(locale='en', timezone=false) }}
+    {{ datetime|format_datetime(locale: 'en', timezone: false) }}
 
 The default timezone can also be set globally by calling ``setTimezone()``::
 
diff --git a/doc/filters/format_number.rst b/doc/filters/format_number.rst
index 994404e07..900fa5ea9 100644
--- a/doc/filters/format_number.rst
+++ b/doc/filters/format_number.rst
@@ -44,10 +44,10 @@ Besides plain numbers, the filter can also format numbers in various styles:
 .. code-block:: twig
 
     {# 1,234% #}
-    {{ '12.345'|format_number(style='percent') }}
+    {{ '12.345'|format_number(style: 'percent') }}
 
     {# twelve point three four five #}
-    {{ '12.345'|format_number(style='spellout') }}
+    {{ '12.345'|format_number(style: 'spellout') }}
 
     {# 12 sec. #}
     {{ '12'|format_duration_number }}
@@ -85,7 +85,7 @@ By default, the filter uses the current locale. You can pass it explicitly:
 .. code-block:: twig
 
     {# 12,345 #}
-    {{ '12.345'|format_number(locale='fr') }}
+    {{ '12.345'|format_number(locale: 'fr') }}
 
 .. note::
 
diff --git a/doc/filters/trim.rst b/doc/filters/trim.rst
index 238928bc7..ba01cbe85 100644
--- a/doc/filters/trim.rst
+++ b/doc/filters/trim.rst
@@ -14,7 +14,7 @@ and end of a string:
 
     {# outputs '  I like Twig' #}
 
-    {{ '  I like Twig.  '|trim(side='left') }}
+    {{ '  I like Twig.  '|trim(side: 'left') }}
 
     {# outputs 'I like Twig.  ' #}
 
diff --git a/doc/templates.rst b/doc/templates.rst
index 2746d90f6..638535614 100644
--- a/doc/templates.rst
+++ b/doc/templates.rst
@@ -210,11 +210,16 @@ built-in functions.
 Named Arguments
 ---------------
 
-Named arguments are supported in functions, filters and tests.
+Named arguments are supported in functions, filters, and tests.
+
+.. versionadded:: 3.12
+
+    Twig supports both ``=`` and ``:`` as separators between argument names and
+    values, but support for ``:`` was introduced in Twig 3.12.
 
 .. code-block:: twig
 
-    {% for i in range(low=1, high=10, step=2) %}
+    {% for i in range(low: 1, high: 10, step: 2) %}
         {{ i }},
     {% endfor %}
 
@@ -227,7 +232,7 @@ the values you pass as arguments:
 
     {# versus #}
 
-    {{ data|convert_encoding(from='iso-2022-jp', to='UTF-8') }}
+    {{ data|convert_encoding(from: 'iso-2022-jp', to: 'UTF-8') }}
 
 Named arguments also allow you to skip some arguments for which you don't want
 to change the default value:
@@ -238,19 +243,19 @@ to change the default value:
     {{ "now"|date(null, "Europe/Paris") }}
 
     {# or skip the format value by using a named argument for the time zone #}
-    {{ "now"|date(timezone="Europe/Paris") }}
+    {{ "now"|date(timezone: "Europe/Paris") }}
 
 You can also use both positional and named arguments in one call, in which
 case positional arguments must always come before named arguments:
 
 .. code-block:: twig
 
-    {{ "now"|date('d/m/Y H:i', timezone="Europe/Paris") }}
+    {{ "now"|date('d/m/Y H:i', timezone: "Europe/Paris") }}
 
 .. tip::
 
-    Each function and filter documentation page has a section where the names
-    of all arguments are listed when supported.
+    Each function, filter, and test documentation page has a section where the
+    names of all supported arguments are listed.
 
 Control Structure
 -----------------
diff --git a/src/ExpressionParser.php b/src/ExpressionParser.php
index 0055e643d..ae210ed6e 100644
--- a/src/ExpressionParser.php
+++ b/src/ExpressionParser.php
@@ -611,7 +611,7 @@ class ExpressionParser
             }
 
             $name = null;
-            if ($namedArguments && $token = $stream->nextIf(Token::OPERATOR_TYPE, '=')) {
+            if ($namedArguments && (($token = $stream->nextIf(Token::OPERATOR_TYPE, '=')) || ($token = $stream->nextIf(Token::PUNCTUATION_TYPE, ':')))) {
                 if (!$value instanceof NameExpression) {
                     throw new SyntaxError(\sprintf('A parameter name must be a string, "%s" given.', $value::class), $token->getLine(), $stream->getSourceContext());
                 }
diff --git a/tests/Fixtures/functions/attribute.test b/tests/Fixtures/functions/attribute.test
index 2f70b08a4..31cca8c46 100644
--- a/tests/Fixtures/functions/attribute.test
+++ b/tests/Fixtures/functions/attribute.test
@@ -3,10 +3,12 @@
 --TEMPLATE--
 {{ attribute(obj, method) }}
 {{ attribute(variable=obj, attribute=method) }}
+{{ attribute(variable: obj, attribute: method) }}
 {{ attribute(array, item) }}
 {{ attribute(obj, "bar", ["a", "b"]) }}
 {{ attribute(obj, "bar", arguments) }}
 {{ attribute(variable=obj, attribute="bar", arguments=arguments) }}
+{{ attribute(variable: obj, attribute: "bar", arguments: arguments) }}
 {{ attribute(obj, method) is defined ? 'ok' : 'ko' }}
 {{ attribute(obj, nonmethod) is defined ? 'ok' : 'ko' }}
 --DATA--
@@ -14,9 +16,11 @@ return ['obj' => new Twig\Tests\TwigTestFoo(), 'method' => 'foo', 'array' => ['f
 --EXPECT--
 foo
 foo
+foo
 bar
 bar_a-b
 bar_a-b
 bar_a-b
+bar_a-b
 ok
 ko
diff --git a/tests/Fixtures/functions/date_namedargs.test b/tests/Fixtures/functions/date_namedargs.test
index 11f60ee8b..819e8326b 100644
--- a/tests/Fixtures/functions/date_namedargs.test
+++ b/tests/Fixtures/functions/date_namedargs.test
@@ -3,9 +3,11 @@
 --TEMPLATE--
 {{ date(date, "America/New_York")|date('d/m/Y H:i:s P', false) }}
 {{ date(timezone="America/New_York", date=date)|date('d/m/Y H:i:s P', false) }}
+{{ date(timezone: "America/New_York", date: date)|date('d/m/Y H:i:s P', false) }}
 --DATA--
 date_default_timezone_set('UTC');
 return ['date' => mktime(13, 45, 0, 10, 4, 2010)]
 --EXPECT--
 04/10/2010 09:45:00 -04:00
 04/10/2010 09:45:00 -04:00
+04/10/2010 09:45:00 -04:00