Same color returns different results

[Avladd]

There seems to be inconsistent return based on the input colors. To be more precise i have this input and threshold is set to 0 :

    firstColor: "rgb(255, 255, 255)",
    secondColor: "rgb(255, 255, 255)"
  }

Expected behaviour:
Return combinations array with first object having contrast set to 1;

Actual behaviour:
Returns empty combinations array;

Meanwhile having the same parameters but this input:

    firstColor: "rgba(255, 255, 255, 1)",
    secondColor: "rgb(255, 255, 255)"
  }

returns the expected combinations array with contrast of 1.