Can we have two type of alerts in an application?

In my application, I have two types of information in the content 1.Critical Alerts 2. Alerts that require user attention - may be or may not be critical, totally depending on the need.

I planned to use the same alert icon, but in two different shades

• Red for critical,
• and Amber for caution

to represent the difference. Any thoughts on this. Is that a good practice to have two different shades of alert icons?