ABSTRACT (OPTIONAL)

Helper utilities are needed for a 2-state toggle Button, A few of these buttons will populate a multi-themed DockedCells toolbar in which both are intended for the Function Repository. Several Button properties (Background, FontColor, and label) shall be selected to provide visual cues on the current state of Button action. This offers flexibility and nice alternatives from the generic "Pressed" Appearance. Helpers would validate or autocorrect user-inputs if possible, else issue an error Message. The solution to this Pattern test shall serve as a model for these helpers.

PATTERN CRITERIA

An argument bgs_List?test is constrained to a Length 2 and its elements by a Pattern test limiting them to any combination of all valid Background values: ColorQ, Automatic, or None.

Edit1: Added ABSTRACT; ColorQ replaces: color names (Symbol), RGBColor, GrayLevel.

PASSING CASES

    pass = ToExpression["e" <> ToString[#]] & /@ Range[9];
    e1 = {None, Automatic};
    e2 = {CMYKColor[1, .75, .25, 0], Cyan};
    e3 = {Black, White};
    e4 = {Green, GrayLevel[.333]};
    e5 = {Darker@Brown, RGBColor[.25, .75, .25]};
    e6 = {Lighter@Pink, Hue[.25]};
    e7 = {Hue["DodgerBlue"], White};
    e8 = {CMYKColor["WhiteSmoke"], Hue["Khaki"]};
    e9 = {RGBColor[0, 0, 0], GrayLevel[1]};

FAILING CASES (Auto-correct if possible or issue a Message)

    fail = ToExpression["f" <> ToString[#]] & /@ Range[9];
    f1 = {};
    f2 = {1};
    f3 = {Silver, Black};
    f4 = {.333, GrayLevel[.333]};
    f5 = {"Darker@Brown", RGBColor[.25, .75, .25]};
    f6 = {Lighter@Pink, automatic};
    f7 = {Hue["GoDodgers"], White};
    f8 = {CMYKColor["SmokeMenthol"], Hue["Khaki"]};
    f9 = {RGBColor[0, 0, 0], GrayLevel[1], Darker@Gray, Lighter@Gray};

Edit2: Reworked both lists, added pass and fail, and refactored code.

THE SOLUTION (Thanks to member Hans Milton)

The pattern-test function bgQ with a simple use-case.

bgQ = (ColorQ@# || # == Automatic || # == None) &;

fn[{a_?bgQ, b_?bgQ}] := "Pass";
fn[_] := "Fail";

The proof of concept test function fn on Pass/Fail cases validate bgQ.

fn[#] & /@ pass (* all Pass as expected *)
fn[#] & /@ fail (* all Fail as expected *)

A WORKING EXAMPLE (As discussed in ABSTRACT)

One of the properties selected for providing a visual cue of toggle Button action state is Background. Therefore, a list of 2 values is required. However, if for example some end-users prefer a styled but static Background they can enter the same value for the 2 list elements or take advantage of some corrections made by the helper validator utility valbgs. The default values for both states is Automatic with a "Pressed" Appearance for state-2. "Pressed" only appears when Background is set to None or Automatic. Any Color Directive even White will disable it.

ClearAll[valbgs, bgQ];
bgQ = (ColorQ@# || # == Automatic || # == None) &;
ToggleAutoSaveButton::invoptbg = "Option Backgrounds  \[Rule] `1`, \
expected a valid Background Option value or a List of 1 or 2 values."; 
valbgs[c_?bgQ] := {c, c};
valbgs[{c_?bgQ}] := {c, Automatic};
valbgs[{a_?bgQ, b_?bgQ}] := {a, b};
valbgs[c_] := Message[ToggleAutoSaveButton::invoptbg, c];

None of the following cases meet all the criteria for a list of 2 Background values, however the helper is successful in correcting them all while validating them.

autocor = ToExpression["c" <> ToString[#]] & /@ Range[0, 5];

c0 = None;
c1 = Automatic;
c2 = Red;
c3 = {None};
c4 = {Automatic};
c5 = {Green};

Column@(valbgs[#] & /@ autocor)

The Out[54]= print with extra curly brackets removed, which generated after transferring results here.

{None, None}
{Automatic, Automatic}
{RGBColor[1, 0, 0], RGBColor[1, 0, 0]}
{None, Automatic},
{Automatic, Automatic},
{RGBColor[0, 1, 0], Automatic}

Edit3: Removed speculative pattern form and intended use. Added sections: SOLUTION and WORKING EXAMPLE.