Use qfieldcloud string.

Author: mohsenD98

src/qml/Nyuki.qml

@@ -67,7 +67,7 @@ Item {
       id: nyukiLeft
       width: 10
       height: 10
-      color: Theme.qfieldCloudBlue
+      color: Theme.qfieldcloudBlue
       x: 84
       y: 84
       radius: 5
@@ -92,7 +92,7 @@ Item {
       id: nyukiRight
       width: 10
       height: 10
-      color: Theme.qfieldCloudBlue
+      color: Theme.qfieldcloudBlue
       x: 106
       y: 84
       radius: 5

src/qml/QFieldCloudScreen.qml

@@ -150,7 +150,7 @@ Page {
 
         Material.accent: {
           if (usage < .9) {
-            return Theme.qfieldCloudBlue;
+            return Theme.qfieldcloudBlue;
           } else if (usage < .975) {
             return Theme.warningColor;
           } else {

src/qml/imports/Theme/Theme.qml

@@ -106,7 +106,7 @@ QtObject {
   property color bookmarkOrange: "orange"
   property color bookmarkRed: "#c0392b"
   property color bookmarkBlue: "#64b5f6"
-  property color qfieldCloudBlue: "#4a6fae"
+  property color qfieldcloudBlue: "#4a6fae"
 
   property color vertexColor: "#FF0000"
   property color vertexColorSemiOpaque: "#40FF0000"