This is a simple JS example that works and I'm trying to "improve" it a little.  

I'm a JS total beginner and I hope I'm not stepping in over my head here.

```
var color1 = prompt("Enter first color: yellow, red or blue");
var color2 = prompt("Enter second color: yellow, red or blue"); 

if (color1 == "yellow" && color2 == "yellow"){
      console.log("mixing of these two colors makes yellow");
    }
if (color1 == "red" && color2 == "red"){
      console.log("mixing of these two colors makes red");
    }
if (color1 == "blue" && color2 == "blue"){
      console.log("mixing of these two colors makes blue");
    }
if (color1 == "yellow" && color2 == "red" || color1 == "red" && color2 == "yellow"){
      console.log("mixing of these two colors makes orange");
    }
if (color1 == "yellow" && color2 == "blue" || color1 == "blue" && color2 == "yellow"){
      console.log("mixing of these two colors makes green");
    }
if (color1 == "blue" && color2 == "red" || color1 == "red" && color2 == "blue"){
      console.log("mixing of these two colors makes purple");
    }

```

What I want to do is not to allow the second prompt to appear until the first prompt is properly (accurately) entered (which is:yellow, red, blue), no matter how many times the user enters the "wrong" value.   

I know that I have to use "while" but I'm not sure how. Tried a couple of times with different approaches, but didn't managed to get desired result.  

Also tried some threads with similar problems but couldn't find solution for this specific problem.   

Any help or suggestions are more than welcome.  

Thank you.