You can change the captcha via the object setting in the controller. It was not very clear how to set it.
public function actions()
{
return [
'error' => [
'class' => 'yii\web\ErrorAction',
],
'captcha' => [
'class' => 'yii\captcha\CaptchaAction',
'fixedVerifyCode' => YII_ENV_TEST ? 'testme' : null,
'offset' => 5,
'height' => 100,
],
];
}
This is a set so far
'captcha' => array(
'class' => 'CCaptchaAction',
'backColor' => 0xFFFFFF, // background color
'foreColor' => 0x000000, // font color
'transparent' => false, // background transparent
'testLimit' => 1, // how many times should the same CAPTCHA be displayed
'minLength' => 6, // min length of generated word
'maxLength' => 7, // max length of generated word
'width' => 100, // width of the CAPTCHA image
'height' => 50, // height of the CAPTCHA image
'offset' => -2, // space between characters
'padding' => 4 // padding around the text
),