diff --git a/menu/drivers/rgui.c b/menu/drivers/rgui.c
index 71571bcff0..307e3802e7 100644
--- a/menu/drivers/rgui.c
+++ b/menu/drivers/rgui.c
@@ -451,11 +451,41 @@ static uint16_t argb32_to_abgr1555(uint32_t col)
 
 static uint16_t argb32_to_rgb5a3(uint32_t col)
 {
-   unsigned a = ((col >> 24) & 0xff) >> 5;
-   unsigned r = ((col >> 16) & 0xff) >> 4;
-   unsigned g = ((col >> 8) & 0xff) >> 4;
-   unsigned b = ((col & 0xff) ) >> 4;
-   return (a << 12) | (r << 8) | (g << 4) | b;
+   /* Extract colour components */
+   unsigned a = (col >> 24) & 0xff;
+   unsigned r = (col >> 16) & 0xff;
+   unsigned g = (col >> 8)  & 0xff;
+   unsigned b = col & 0xff;
+   /* Gekko platforms only have a 3 bit alpha channel, which
+    * is one bit less than all 'standard' target platforms.
+    * As a result, Gekko colours are effectively ~6-7% less
+    * transparent than expected, which causes backgrounds and
+    * borders to appear too bright. We therefore have to darken
+    * each RGB component according to the difference between Gekko
+    * alpha and normal 4 bit alpha values... */
+   unsigned a4 = a >> 4;
+   unsigned a3 = a >> 5;
+   float a_factor = 1.0;
+   if (a3 > 0)
+   {
+      /* Avoid divide by zero errors... */
+      a_factor = ((float)a4 * (1.0 / 15.0)) / ((float)a3 * (1.0 / 7.0));
+   }
+   r = (unsigned)(((float)r * a_factor) + 0.5);
+   g = (unsigned)(((float)g * a_factor) + 0.5);
+   b = (unsigned)(((float)b * a_factor) + 0.5);
+   /* a_factor can actually be greater than 1. This will never happen
+    * with the current preset theme colour values, but users can set
+    * any custom values they like, so we have to play it safe... */
+   r = (r <= 0xff) ? r : 0xff;
+   g = (g <= 0xff) ? g : 0xff;
+   b = (b <= 0xff) ? b : 0xff;
+   /* Convert RGB from 8 bit to 4 bit */
+   r = r >> 4;
+   g = g >> 4;
+   b = b >> 4;
+   /* Return final value */
+   return (a3 << 12) | (r << 8) | (g << 4) | b;
 }
 
 #define argb32_to_pixel_platform_format(color) argb32_to_rgb5a3(color)