diff --git a/umap/static/umap/base.css b/umap/static/umap/base.css
index bb86cc79..119ff4ba 100644
--- a/umap/static/umap/base.css
+++ b/umap/static/umap/base.css
@@ -31,7 +31,7 @@ hr {
     -moz-border-left-colors: none;
     -moz-border-right-colors: none;
     -moz-border-top-colors: none;
-    border-color: #ddd;
+    border-color: var(--color-lightGray);
     border-image: none;
     border-style: solid;
     border-width: 1px 0 0;
@@ -223,7 +223,7 @@ button.flat,
     padding: 7px 7px;
     margin-bottom: 14px;
     background: #393F3F;
-    color: #ddd;
+    color: var(--color-lightGray);
     font-size: 10px;
     border-radius: 0 2px;
 }
@@ -264,7 +264,7 @@ input + .error {
     padding: 7px 7px;
     margin-top: -14px;
     margin-bottom: 14px;
-    background: #ddd;
+    background: var(--color-lightGray);
     color: #fff;
     background-color: #cc0000;
     font-size: 11px;
@@ -685,7 +685,7 @@ input[type=hidden].blur + [type="button"] {
     position: absolute;
     bottom: 0;
     padding: 0 10px;
-    border-left: 1px solid #ddd;
+    border-left: 1px solid var(--color-lightGray);
     overflow-x: auto;
     z-index: 1010;
     background-color: #fff;
@@ -698,7 +698,7 @@ input[type=hidden].blur + [type="button"] {
 }
 #umap-ui-container.dark {
     border-left: 1px solid #222;
-    background-color: #323737;
+    background-color: var(--color-darkGray);
     color: #efefef;
 }
 #umap-ui-container.fullwidth {
@@ -913,7 +913,7 @@ input:invalid {
     color: #eeeeec;
     padding: 0 7px;
     line-height: 32px;
-    background-color: #323737;
+    background-color: var(--color-darkGray);
 }
 .dark .umap-close-link:hover {
     background-color: #2e3436;
diff --git a/umap/static/umap/content.css b/umap/static/umap/content.css
index f777bc93..f7b032e3 100644
--- a/umap/static/umap/content.css
+++ b/umap/static/umap/content.css
@@ -150,12 +150,12 @@ h2.section {
 }
 h2.tabs {
     text-transform: uppercase;
-    color: #263B58;
+    color: var(--color-darkBlue);
     text-align: left;
     padding-top: 28px;
 }
 h2.tabs a {
-    color: #263B58;
+    color: var(--color-darkBlue);
     text-decoration: underline;
     text-decoration-thickness: 3px;
     text-decoration-skip-ink: none;
@@ -164,7 +164,7 @@ h2.tabs a {
 }
 h2.tabs a:not(.selected) {
     font-weight: normal;
-    color: #263B58;
+    color: var(--color-darkBlue);
     text-decoration: none;
     margin-right: 0;
 }
@@ -205,8 +205,8 @@ body.content #umap-ui-container {
 
 input[type="submit"],
 .button {
-    background-color: #B9F5D2;
-    color: #263B58;
+    background-color: var(--button-primary-background);
+    color: var(--button-primary-color);
 }
 .button-primary {
     font-weight: bold;
@@ -215,8 +215,8 @@ input[type="submit"],
     background-color: #35537c;
 }
 .wrapper .neutral, .wrapper input[type="submit"].neutral {
-    background-color: #ddd;
-    color: #323737;
+    background-color: var(--button-neutral-background);
+    color: var(--button-neutral-color);
 }
 .wrapper.somber {
     background-color: #2E3641;
@@ -399,7 +399,7 @@ ul.umap-autocomplete {
     }
 }
 .table-header form input {
-    border: 2px solid #263B58;
+    border: 2px solid var(--color-darkBlue);
     border-radius: 0;
     padding: .5rem 1rem;
     margin-bottom: 0;
@@ -410,7 +410,7 @@ ul.umap-autocomplete {
     width: 30ch;
 }
 .table-header form input[type="submit"] {
-    background-color: #263B58;
+    background-color: var(--color-darkBlue);
     color: white;
     font-weight: bold;
 }
@@ -419,8 +419,8 @@ ul.umap-autocomplete {
     width: inherit;
     display: inline;
     padding: .5rem 1rem;
-    border: 2px solid #263B58;
-    color: #263B58;
+    border: 2px solid var(--color-darkBlue);
+    color: var(--color-darkBlue);
     font-weight: bold;
     background-color: initial;
     margin-bottom: 0;
@@ -443,7 +443,7 @@ ul.umap-autocomplete {
 .table-wrapper table a,
 .table-wrapper table thead tr th,
 .table-wrapper table th[scope="row"] {
-    color: #263B58;
+    color: var(--color-darkBlue);
     text-align: left;
     padding-left: 2px;
 }
@@ -469,7 +469,7 @@ ul.umap-autocomplete {
 .table-wrapper table input[type="submit"] {
     display: inline;
     background-color: transparent;
-    color: #263B58;
+    color: var(--color-darkBlue);
     padding: 0;
     width: inherit;
     height: 1rem;
@@ -527,7 +527,7 @@ dialog::backdrop {
     padding: 1rem;
 }
 .pagination a {
-    color: #263B58;
+    color: var(--color-darkBlue);
     text-decoration: underline;
 }
 
diff --git a/umap/static/umap/map.css b/umap/static/umap/map.css
index 86259db7..f6a643a6 100644
--- a/umap/static/umap/map.css
+++ b/umap/static/umap/map.css
@@ -13,7 +13,7 @@
     * Same as leaflet background, to work around screen blincking
     * between DOM is loaded and JS is read to render the map.
     */
-    background-color: #ddd;
+    background-color: var(--color-lightGray);
 }
 
 
@@ -293,7 +293,7 @@ ul.photon-autocomplete {
     margin-top: 0;
     vertical-align: top;
     border-bottom: none;
-    background-color: #323737;
+    background-color: var(--color-darkGray);
     border-right: 1px solid #eee;
     background-repeat: no-repeat;
     background-image: url('./img/24.svg');
@@ -446,7 +446,7 @@ ul.photon-autocomplete {
     max-width: 100vw;
     padding: 40px 20px;
     border: 1px solid #222;
-    background-color: #323737;
+    background-color: var(--color-darkGray);
     color: #efefef;
     font-size: 0.8em;
     visibility: hidden;
@@ -464,7 +464,7 @@ ul.photon-autocomplete {
     background-position: -4px -4px;
     background-repeat: no-repeat;
     background-image: url('./img/16.svg');
-    background-color: #323737 !important;
+    background-color: var(--color-darkGray) !important;
     vertical-align: middle;
     text-indent: -9999px;
     min-height: inherit;
@@ -518,7 +518,7 @@ ul.photon-autocomplete {
     color: #fff;
     font-size: 1.2em;
     border: none;
-    background-color: #323737;
+    background-color: var(--color-darkGray);
     width: auto;
     margin-bottom: 0;
 }
@@ -625,7 +625,7 @@ ul.photon-autocomplete {
     left: 0;
     right: 0;
     height: 46px;
-    background-color: #323737;
+    background-color: var(--color-darkGray);
     padding: 0 10px;
     text-align: left;
     line-height: 36px;
@@ -728,7 +728,7 @@ ul.photon-autocomplete {
     text-align: left;
     line-height: 46px;
     cursor: auto;
-    border-top: 1px solid #ddd;
+    border-top: 1px solid var(--color-lightGray);
     opacity: 0.93;
     z-index: 1000;
 }
@@ -884,10 +884,10 @@ ul.photon-autocomplete {
 }
 .leaflet-inplace-toolbar a {
     background-image: url('./img/16-white.svg');
-    background-color: #323737!important;
+    background-color: var(--color-darkGray)!important;
 }
 .leaflet-toolbar-tip {
-    background-color: #323737;
+    background-color: var(--color-darkGray);
 }
 .leaflet-inplace-toolbar a:hover {
     background-color: #353c3e!important;
diff --git a/umap/static/umap/nav.css b/umap/static/umap/nav.css
index 3c754d3f..d052e112 100644
--- a/umap/static/umap/nav.css
+++ b/umap/static/umap/nav.css
@@ -36,7 +36,7 @@ footer .i18n_switch {
     flex-direction: column;
 }
 .umap-nav a {
-    color: #263B58;
+    color: var(--color-darkBlue);
     padding: .4rem;
 }
 .umap-nav a:hover {
diff --git a/umap/static/umap/test/index.html b/umap/static/umap/test/index.html
index 23c9d52f..86364301 100644
--- a/umap/static/umap/test/index.html
+++ b/umap/static/umap/test/index.html
@@ -62,6 +62,7 @@
     <link rel="stylesheet" href="../vendors/locatecontrol/L.Control.Locate.min.css" />
     <link rel="stylesheet" href="../vendors/iconlayers/iconLayers.css" />
 
+    <link rel="stylesheet" href="../../umap/vars.css" />
     <link rel="stylesheet" href="../../umap/font.css" />
     <link rel="stylesheet" href="../../umap/base.css" />
     <link rel="stylesheet" href="../../umap/content.css" />
diff --git a/umap/static/umap/vars.css b/umap/static/umap/vars.css
new file mode 100644
index 00000000..c72a52ac
--- /dev/null
+++ b/umap/static/umap/vars.css
@@ -0,0 +1,13 @@
+:root {
+    /* Colors. */
+    --color-waterMint: #B9F5D2;
+    --color-darkBlue: #263B58;
+    --color-lightGray: #ddd;
+    --color-darkGray: #323737;
+
+    /* Buttons. */
+    --button-primary-background: var(--color-waterMint);
+    --button-primary-color: var(--color-darkBlue);
+    --button-neutral-background: var(--color-lightGray);
+    --button-neutral-color: var(--color-darkGray);
+}
diff --git a/umap/templates/umap/css.html b/umap/templates/umap/css.html
index df51e526..8c1af26d 100644
--- a/umap/templates/umap/css.html
+++ b/umap/templates/umap/css.html
@@ -21,6 +21,7 @@
       href="{% static 'umap/vendors/locatecontrol/L.Control.Locate.min.css' %}" />
 <link rel="stylesheet"
       href="{% static 'umap/vendors/iconlayers/iconLayers.css' %}" />
+<link rel="stylesheet" href="{% static 'umap/vars.css' %}" />
 <link rel="stylesheet" href="{% static 'umap/font.css' %}" />
 <link rel="stylesheet" href="{% static 'umap/base.css' %}" />
 <link rel="stylesheet" href="{% static 'umap/content.css' %}" />