chore: regens API reference docs (#889)

diff --git a/docs/dyn/sheets_v4.spreadsheets.sheets.html b/docs/dyn/sheets_v4.spreadsheets.sheets.html
index 4dcf74c..dc01d7f 100644
--- a/docs/dyn/sheets_v4.spreadsheets.sheets.html
+++ b/docs/dyn/sheets_v4.spreadsheets.sheets.html
@@ -75,18 +75,18 @@
 <h1><a href="sheets_v4.html">Google Sheets API</a> . <a href="sheets_v4.spreadsheets.html">spreadsheets</a> . <a href="sheets_v4.spreadsheets.sheets.html">sheets</a></h1>
 <h2>Instance Methods</h2>
 <p class="toc_element">
-  <code><a href="#copyTo">copyTo(spreadsheetId, sheetId, body, x__xgafv=None)</a></code></p>
+  <code><a href="#copyTo">copyTo(spreadsheetId, sheetId, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Copies a single sheet from a spreadsheet to another spreadsheet.</p>
 <h3>Method Details</h3>
 <div class="method">
-    <code class="details" id="copyTo">copyTo(spreadsheetId, sheetId, body, x__xgafv=None)</code>
+    <code class="details" id="copyTo">copyTo(spreadsheetId, sheetId, body=None, x__xgafv=None)</code>
   <pre>Copies a single sheet from a spreadsheet to another spreadsheet.
 Returns the properties of the newly created sheet.
 
 Args:
   spreadsheetId: string, The ID of the spreadsheet containing the sheet to copy. (required)
   sheetId: integer, The ID of the sheet to copy. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # The request to copy a sheet across spreadsheets.
@@ -198,14 +198,14 @@
         #
         #      static Color* toProto(UIColor* color) {
         #          CGFloat red, green, blue, alpha;
-        #          if (![color getRed:&red green:&green blue:&blue alpha:&alpha]) {
+        #          if (![color getRed:&amp;red green:&amp;green blue:&amp;blue alpha:&amp;alpha]) {
         #            return nil;
         #          }
         #          Color* result = [[Color alloc] init];
         #          [result setRed:red];
         #          [result setGreen:green];
         #          [result setBlue:blue];
-        #          if (alpha <= 0.9999) {
+        #          if (alpha &lt;= 0.9999) {
         #            [result setAlpha:floatWrapperWithValue(alpha)];
         #          }
         #          [result autorelease];
@@ -235,11 +235,11 @@
         #     };
         #
         #     var rgbToCssColor_ = function(red, green, blue) {
-        #       var rgbNumber = new Number((red << 16) | (green << 8) | blue);
+        #       var rgbNumber = new Number((red &lt;&lt; 16) | (green &lt;&lt; 8) | blue);
         #       var hexString = rgbNumber.toString(16);
         #       var missingZeros = 6 - hexString.length;
         #       var resultBuilder = ['#'];
-        #       for (var i = 0; i < missingZeros; i++) {
+        #       for (var i = 0; i &lt; missingZeros; i++) {
         #          resultBuilder.push('0');
         #       }
         #       resultBuilder.push(hexString);
@@ -263,6 +263,144 @@
       "red": 3.14, # The amount of red in the color as a value in the interval [0, 1].
     },
     "hidden": True or False, # True if the sheet is hidden in the UI, false if it's visible.
+    "tabColorStyle": { # A color value. # The color of the tab in the UI.
+        # If tab_color is also set, this field takes precedence.
+      "themeColor": "A String", # Theme color.
+      "rgbColor": { # Represents a color in the RGBA color space. This representation is designed # RGB color.
+          # for simplicity of conversion to/from color representations in various
+          # languages over compactness; for example, the fields of this representation
+          # can be trivially provided to the constructor of "java.awt.Color" in Java; it
+          # can also be trivially provided to UIColor's "+colorWithRed:green:blue:alpha"
+          # method in iOS; and, with just a little work, it can be easily formatted into
+          # a CSS "rgba()" string in JavaScript, as well.
+          #
+          # Note: this proto does not carry information about the absolute color space
+          # that should be used to interpret the RGB value (e.g. sRGB, Adobe RGB,
+          # DCI-P3, BT.2020, etc.). By default, applications SHOULD assume the sRGB color
+          # space.
+          #
+          # Example (Java):
+          #
+          #      import com.google.type.Color;
+          #
+          #      // ...
+          #      public static java.awt.Color fromProto(Color protocolor) {
+          #        float alpha = protocolor.hasAlpha()
+          #            ? protocolor.getAlpha().getValue()
+          #            : 1.0;
+          #
+          #        return new java.awt.Color(
+          #            protocolor.getRed(),
+          #            protocolor.getGreen(),
+          #            protocolor.getBlue(),
+          #            alpha);
+          #      }
+          #
+          #      public static Color toProto(java.awt.Color color) {
+          #        float red = (float) color.getRed();
+          #        float green = (float) color.getGreen();
+          #        float blue = (float) color.getBlue();
+          #        float denominator = 255.0;
+          #        Color.Builder resultBuilder =
+          #            Color
+          #                .newBuilder()
+          #                .setRed(red / denominator)
+          #                .setGreen(green / denominator)
+          #                .setBlue(blue / denominator);
+          #        int alpha = color.getAlpha();
+          #        if (alpha != 255) {
+          #          result.setAlpha(
+          #              FloatValue
+          #                  .newBuilder()
+          #                  .setValue(((float) alpha) / denominator)
+          #                  .build());
+          #        }
+          #        return resultBuilder.build();
+          #      }
+          #      // ...
+          #
+          # Example (iOS / Obj-C):
+          #
+          #      // ...
+          #      static UIColor* fromProto(Color* protocolor) {
+          #         float red = [protocolor red];
+          #         float green = [protocolor green];
+          #         float blue = [protocolor blue];
+          #         FloatValue* alpha_wrapper = [protocolor alpha];
+          #         float alpha = 1.0;
+          #         if (alpha_wrapper != nil) {
+          #           alpha = [alpha_wrapper value];
+          #         }
+          #         return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
+          #      }
+          #
+          #      static Color* toProto(UIColor* color) {
+          #          CGFloat red, green, blue, alpha;
+          #          if (![color getRed:&amp;red green:&amp;green blue:&amp;blue alpha:&amp;alpha]) {
+          #            return nil;
+          #          }
+          #          Color* result = [[Color alloc] init];
+          #          [result setRed:red];
+          #          [result setGreen:green];
+          #          [result setBlue:blue];
+          #          if (alpha &lt;= 0.9999) {
+          #            [result setAlpha:floatWrapperWithValue(alpha)];
+          #          }
+          #          [result autorelease];
+          #          return result;
+          #     }
+          #     // ...
+          #
+          #  Example (JavaScript):
+          #
+          #     // ...
+          #
+          #     var protoToCssColor = function(rgb_color) {
+          #        var redFrac = rgb_color.red || 0.0;
+          #        var greenFrac = rgb_color.green || 0.0;
+          #        var blueFrac = rgb_color.blue || 0.0;
+          #        var red = Math.floor(redFrac * 255);
+          #        var green = Math.floor(greenFrac * 255);
+          #        var blue = Math.floor(blueFrac * 255);
+          #
+          #        if (!('alpha' in rgb_color)) {
+          #           return rgbToCssColor_(red, green, blue);
+          #        }
+          #
+          #        var alphaFrac = rgb_color.alpha.value || 0.0;
+          #        var rgbParams = [red, green, blue].join(',');
+          #        return ['rgba(', rgbParams, ',', alphaFrac, ')'].join('');
+          #     };
+          #
+          #     var rgbToCssColor_ = function(red, green, blue) {
+          #       var rgbNumber = new Number((red &lt;&lt; 16) | (green &lt;&lt; 8) | blue);
+          #       var hexString = rgbNumber.toString(16);
+          #       var missingZeros = 6 - hexString.length;
+          #       var resultBuilder = ['#'];
+          #       for (var i = 0; i &lt; missingZeros; i++) {
+          #          resultBuilder.push('0');
+          #       }
+          #       resultBuilder.push(hexString);
+          #       return resultBuilder.join('');
+          #     };
+          #
+          #     // ...
+        "blue": 3.14, # The amount of blue in the color as a value in the interval [0, 1].
+        "alpha": 3.14, # The fraction of this color that should be applied to the pixel. That is,
+            # the final pixel color is defined by the equation:
+            #
+            #   pixel color = alpha * (this color) + (1.0 - alpha) * (background color)
+            #
+            # This means that a value of 1.0 corresponds to a solid color, whereas
+            # a value of 0.0 corresponds to a completely transparent color. This
+            # uses a wrapper message rather than a simple float scalar so that it is
+            # possible to distinguish between a default value and the value being unset.
+            # If omitted, this color object is to be rendered as a solid color
+            # (as if the alpha value had been explicitly given with a value of 1.0).
+        "green": 3.14, # The amount of green in the color as a value in the interval [0, 1].
+        "red": 3.14, # The amount of red in the color as a value in the interval [0, 1].
+      },
+    },
     "sheetId": 42, # The ID of the sheet. Must be non-negative.
         # This field cannot be changed once set.
   }</pre>