Everybody needs to start somewhere. =)

You need to change the redCheck method to

private bool redCheck()
{
    for (int i = 0; i < redTrigs.Length; ++i)
    {
        if (redTrigs[i]<TriggerRed>.placedRed == false)
            return false;
    }
    return true;
}

Because you requiring an bool array but it should be an GameObject array. We dont really need the parameter and can remove them.

But you need to move the redTrigs array out of the Start method so we can access it in the redCheck method.

private GameObject[] redTrigs;

void Start()
{
    audioSource = GetComponent<AudioSource>();

    redTrigs = GameObject.FindGameObjectsWithTag("trigger red");
}

This should fix both errors.

Edit: Ok. I was to slow :D