Bom dia,
Edita o arquivo com o seguinte comando:sudo nano /usr/share/zentyal/www//default.theme
Apaga tudo que está la dentro e coloca o seguinte:___________________________________________________________________
remote_svcs_bg_color: "# BBE03A"
remote_svcs_hover_bg_color: "# CCE86C"
main_color: "#69BE28"
main_color_darker: "#46962D"
main_color_lighter: "#9fd575"
secondary_color: "#ff7900"
secondary_color_darker: "#c35F00"
secondary_color_lighter: "#f7ad6d"
third_color: "#00add0"
third_color_darker: "#008745"
third_color_lighter: "#4bd0eb"
# login.css
logo_style: "float: left;"
body_background_color: "#eee"
loginin_padding_style: "15px 30px 15px 30px"
# public.css
header_img_padding: "padding-top: 0; padding-left: 0;"
hmenu_bg_color: "#46962D"
hmenu_hover_bg_color: "#69BE28"
footer_custom_style: "text-align: center;"
data_table_border_color: "#69BE28"
data_table_inner_border_color: "#eee"
data_table_color: "#000"
data_table_bg_color: "#fff"
data_table_bg_even: "#fff"
data_table_bg_highlight: "#FFC200"
data_table_bg_highlight_hover: "#FFB800"
msg_bg_color: "#06BC06"
helpbutton_color: "#859E83"
nav_li_color: "#333333"
a_notchanged_hover_color: "#CBF23E"
dashboard_thead_bg_color: "#808000"
progress_bar_bg_color: "#69BE28"
progress_bar_fg_color: "#white"
# tooltips
help_color: "#00529B"
help_background: "#BDE5F8"
help_border: "#00529B"
note_color: "#4F8A10"
note_background: "#DFF2BF"
note_border: "#4F8A10"
error_color: "#D8000C"
error_background: "#FFBABA"
error_border: "#D8000C"
warn_color: "#9F6000"
warn_background: "#FEEFB3"
warn_border: "#9F6000"
ad_color: "#484554"
ad_background: "#dfef7a"
ad_border: "#a9c500"
ad_extra_style: ""
additional_footer_style: ""
# images
favicon: "/favicon.ico"
image_title: "/data/images/title.png"
image_note: "/data/images/msg.png"
# login/index.mas
image_login_logo: "/data/images/title-login.png"
alt_logo: "Zentyal Logo"
created_by_footer: "Created by <a href=\"
http://www.zentyal.com/\">Zentyal S.L.</a>"
# footer.mas
copyright_footer: "Created by <a href=\"
http://www.zentyal.com/\">Zentyal S.L.</a>"
__________________________________________________________________________
Depois reinicia o webadmin com o seguinte comando:sudo /etc/init.d/zentyal webadmin restart