8 string references to 'Custom'

Boolean::init in drupal/core/modules/views/lib/Drupal/views/Plugin/views/field/Boolean.php
Overrides \Drupal\views\Plugin\views\field\FieldPluginBase::init().
color_scheme_form in drupal/core/modules/color/color.module
Form constructor for the color configuration form for a particular theme.
Date::buildOptionsForm in drupal/core/modules/views/lib/Drupal/views/Plugin/views/field/Date.php
Default options form that provides the label widget that all fields should have.
Time::buildOptionsForm in drupal/core/modules/views/lib/Drupal/views/Plugin/views/cache/Time.php
Provide a form to edit options for this plugin.
ValidationVisitorTest::testValidateTwiceInDifferentGroupsValidatesTwice in drupal/core/vendor/symfony/validator/Symfony/Component/Validator/Tests/ValidationVisitorTest.php
ValidatorTest::testValidateDefaultGroup in drupal/core/vendor/symfony/validator/Symfony/Component/Validator/Tests/ValidatorTest.php
ValidatorTest::testValidateOneGroup in drupal/core/vendor/symfony/validator/Symfony/Component/Validator/Tests/ValidatorTest.php
views.field.schema.yml in drupal/core/modules/views/config/schema/views.field.schema.yml
drupal/core/modules/views/config/schema/views.field.schema.yml