diff --git a/menu/drivers/rgui.c b/menu/drivers/rgui.c
index b9b6cee016..12cbc3286e 100644
--- a/menu/drivers/rgui.c
+++ b/menu/drivers/rgui.c
@@ -417,11 +417,32 @@ static uint16_t *rgui_framebuf_data      = NULL;
 
 static uint16_t argb32_to_abgr1555(uint32_t col)
 {
-   unsigned a = ((col >> 24) & 0xff) >> 7;
-   unsigned r = ((col >> 16) & 0xff) >> 3;
-   unsigned g = ((col >> 8)  & 0xff) >> 3;
-   unsigned b = ((col & 0xff)      ) >> 3;
-   return (a << 15) | (b << 10) | (g << 5) | r;
+   /* Extract colour components */
+   unsigned a = (col >> 24) & 0xff;
+   unsigned r = (col >> 16) & 0xff;
+   unsigned g = (col >> 8)  & 0xff;
+   unsigned b = col & 0xff;
+   /* Background and border colours are normally semi-transparent
+    * (so we can see suspended content when opening the quick menu).
+    * When no content is loaded, the 'image' behind the RGUI background
+    * and border is black - which has the effect of darkening the
+    * perceived background/border colours. All the preset theme (and
+    * default 'custom') colour values have been adjusted to account for
+    * this, but abgr1555 only has a 1 bit alpha channel. This means all
+    * colours become fully opaque, and consequently backgrounds/borders
+    * become abnormally bright.
+    * We therefore have to darken each RGB value according to the alpha
+    * component of the input colour... */
+   float a_factor = (float)a * (1.0 / 255.0);
+   r = (unsigned)(((float)r * a_factor) + 0.5) & 0xff;
+   g = (unsigned)(((float)g * a_factor) + 0.5) & 0xff;
+   b = (unsigned)(((float)b * a_factor) + 0.5) & 0xff;
+   /* Convert from 8 bit to 5 bit */
+   r = r >> 3;
+   g = g >> 3;
+   b = b >> 3;
+   /* Return final value - alpha always set to 1 */
+   return (1 << 15) | (b << 10) | (g << 5) | r;
 }
 
 #define argb32_to_pixel_platform_format(color) argb32_to_abgr1555(color)