create tertiary-background-color class

packages/rocketchat-theme/server/colors.less

@@ -106,6 +106,13 @@
 .background-attention-color {
 	background-color: @attention-color;
 }
+
+// Minor Colors
+
+.tertiary-background-color {
+	background-color: @tertiary-background-color;
+}
+
 // transparent
 
 .background-transparent-darkest {
@@ -368,11 +375,8 @@ a:hover {
 }
 
 .avatar-suggestion-item {
-	background-color: @tertiary-background-color;
-
 	.avatar {
 		background-size: cover;
-		background-color: @tertiary-background-color;
 	}
 
 	.question-mark::before {

packages/rocketchat-ui-account/account/avatar/prompt.html

 <template name="avatarSuggestion">
 	{{#if .}}
-		<div class="avatar-suggestion-item">
-			<div class="avatar" style="background-image: url({{blob}});">
+		<div class="avatar-suggestion-item tertiary-background-color">
+			<div class="avatar tertiary-background-color" style="background-image: url({{blob}});">
 			</div>
 			<div class="action">
 				<button type="button" class="button primary {{service}} select-service">{{_ "Use_service_avatar" service}}</button>
@@ -12,8 +12,8 @@
 
 <template name="avatarSuggestionLogin">
 	{{#if .}}
-		<div class="avatar-suggestion-item">
-			<div class="avatar question-mark icon-user"></div>
+		<div class="avatar-suggestion-item tertiary-background-color">
+			<div class="avatar question-mark icon-user tertiary-background-color"></div>
 			<div class="action">
 				<button type="button" class="button primary {{.}} login-with-service">{{_ "Login_with" .}}</button>
 			</div>
@@ -36,7 +36,7 @@
 				</header>
 				<div>
 					<div class="avatar-suggestions">
-						<div class="avatar-suggestion-item">
+						<div class="avatar-suggestion-item tertiary-background-color">
 							{{> avatar username=initialsUsername }}
 							{{#with service='initials'}}
 								<div class="action">
@@ -44,8 +44,8 @@
 								</div>
 							{{/with}}
 						</div>
-						<div class="avatar-suggestion-item">
-							<div style="background-image: url({{upload.blob}});" class="avatar {{#unless upload}}question-mark icon-upload{{/unless}}">
+						<div class="avatar-suggestion-item tertiary-background-color">
+							<div style="background-image: url({{upload.blob}});" class="avatar tertiary-background-color {{#unless upload}}question-mark icon-upload{{/unless}}">
 							</div>
 							<div class="action">
 								<div class="button primary">{{_ "Select_file"}}
@@ -56,9 +56,9 @@
 								{{/with}}
 							</div>
 						</div>
-						<div class="avatar-suggestion-item">
+						<div class="avatar-suggestion-item tertiary-background-color">
 							{{#with service='url'}}
-								<div class="avatar question-mark icon-upload"></div>
+								<div class="avatar question-mark icon-upload tertiary-background-color"></div>
 								<div class="action">
 									<div class="input-line">
 										<input type="text" name="avatarurl" id="avatarurl" />