def prep_nnet_arch(n_depth, n_size, activation, colormode, alpha):
    layers = [5] #x, y, r, z1, z2
    for i in range(n_depth):
        layers.append(n_size)

    colormode = colormode.lower()

    ### Output layer. Append number of output neurons depending on which colormode is selected
    if colormode in ["rgb", "hsv", "hsl"] : #RGB
        if not alpha:
            layers.append(3)
        else:
            layers.append(4)
    elif colormode == "cmyk":
        if not alpha:
            layers.append(4)
        else:
            layers.append(5)
    elif colormode == "bw":
        if not alpha:
            layers.append(1)
        else:
            layers.append(2)
    else:
        print("Inserted colormode '{}' is not part ob supported ones: [rgb, bw, cmyk, hsv, hsl]".format(colormode))
        raise Exception("Non-supported colormode {}".format(colormode))

    possibles = ["sigmoid", "tanh", "relu", "identity", "softsign", "sin", "cos", "softmax"]
    if not activation.lower() in possibles:
        print('defined activation {} not supported in {}'.format(activation, str(possibles)))
        return None

    activations_fnc = [activation] * (len(layers)-2)
    activations_fnc.append("sigmoid")

    return layers, activations_fnc