Invalid value for background does not throw error

[Pranomvignesh]

I am using csslint npm package -v1.0.5
This is my test code .

var csslint = require("csslint");
var linted = csslint.CSSLint.verify(`
.sample{
    background:efwf;
}
`);
console.log(linted.messages)

Output :

[]

I have tried this in csslint website

When i tried the same in https://jigsaw.w3.org/css-validator/validator, I am getting expected results.

Do i have to configure something in csslint to achieve the same as i expect ? Correct me if i am wrong.