diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Card/AbpCardBodyTagHelperService.cs b/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Card/AbpCardBodyTagHelperService.cs
index e50d0a791a..b8462f4b5b 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Card/AbpCardBodyTagHelperService.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Card/AbpCardBodyTagHelperService.cs
@@ -32,7 +32,7 @@ public class AbpCardBodyTagHelperService : AbpTagHelperService<AbpCardBodyTagHel
         if (!TagHelper.Subtitle.IsNullOrWhiteSpace())
         {
             var cardSubtitle = new TagBuilder(AbpCardSubtitleTagHelper.DefaultHeading.ToHtmlTag());
-            cardSubtitle.AddCssClass("card-subtitle text-muted mb-2");
+            cardSubtitle.AddCssClass("card-subtitle mb-2");
             cardSubtitle.InnerHtml.AppendHtml(TagHelper.Subtitle!);
             output.PreContent.AppendHtml(cardSubtitle);
         }
diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/AbpSelectTagHelperService.cs b/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/AbpSelectTagHelperService.cs
index b7777f48e0..248a217495 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/AbpSelectTagHelperService.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/AbpSelectTagHelperService.cs
@@ -250,7 +250,7 @@ public class AbpSelectTagHelperService : AbpTagHelperService<AbpSelectTagHelper>
 
         var small = new TagBuilder("small");
         small.Attributes.Add("id", idAttr?.Value?.ToString() + "InfoText");
-        small.AddCssClass("form-text text-muted");
+        small.AddCssClass("form-text");
         small.InnerHtml.Append(localizedText);
 
         return small.ToHtmlString();