diff --git a/render.c b/render.c
index 603925e..65f5b4b 100644
--- a/render.c
+++ b/render.c
@@ -89,7 +89,7 @@ render_page(render_thread_t* render_thread, zathura_page_t* page)
   return true;
 }
 
-void
+static void
 color2double(GdkColor* col, double* v)
 {
   v[0] = (double) col->red / 65535.;
@@ -100,7 +100,7 @@ color2double(GdkColor* col, double* v)
 /* Returns the maximum possible saturation for given h and l.
    Assumes that l is in the interval l1, l2 and corrects the value to
    force u=0 on l1 and l2 */
-double
+static double
 colorumax(double* h, double l, double l1, double l2)
 {
   double u, uu, v, vv, lv;
@@ -109,27 +109,33 @@ colorumax(double* h, double l, double l1, double l2)
   }
 
   lv = (l - l1)/(l2 - l1);    /* Remap l to the whole interval 0,1 */
-  
   u = v = 1000000;
   for (int k = 0; k < 3; k++) {
     if (h[k] > 0) {
       uu = fabs((1-l)/h[k]);
       vv = fabs((1-lv)/h[k]);
-      
-      if (uu < u)    u = uu;
-      if (vv < v) v = vv;
 
+      if (uu < u) {
+        u = uu;
+      }
+      if (vv < v) {
+        v = vv;
+      }
     } else if (h[k] < 0) {
       uu = fabs(l/h[k]);
       vv = fabs(lv/h[k]);
 
-      if (uu < u)    u = uu;
-      if (vv < v) v = vv;      
+      if (uu < u) {
+        u = uu;
+      }
+      if (vv < v) {
+        v = vv;
+      }
     }
   }
 
   /* rescale v according to the length of the interval [l1, l2] */
-  v = fabs(l2 - l1) * v; 
+  v = fabs(l2 - l1) * v;
 
   /* forces the returned value to be 0 on l1 and l2, trying not to distort colors too much */
   return fmin(u, v);
@@ -194,62 +200,63 @@ render(zathura_t* zathura, zathura_page_t* page)
      - a hue vector, which indicates a radian direction from the grey axis, inside the equal lightness plane.
      - a saturation scalar between 0,1. It is 0 when grey, 1 when the color is in the boundary of the rgb cube.
   */
-   
   if (zathura->global.recolor == true) {
-
     /* RGB weights for computing lightness. Must sum to one */
     double a[] = {0.30, 0.59, 0.11};
 
     double l1, l2, l, s, u, t;
-    double h[3];   
+    double h[3];
     double rgb1[3], rgb2[3], rgb[3];
-    
+
     color2double(&zathura->ui.colors.recolor_dark_color, rgb1);
     color2double(&zathura->ui.colors.recolor_light_color, rgb2);
 
     l1 = (a[0]*rgb1[0] + a[1]*rgb1[1] + a[2]*rgb1[2]);
     l2 = (a[0]*rgb2[0] + a[1]*rgb2[1] + a[2]*rgb2[2]);
-       
+
     for (unsigned int y = 0; y < page_height; y++) {
       unsigned char* data = image + y * rowstride;
 
-      for (unsigned int x = 0; x < page_width; x++) {	
-	/* Careful. data color components blue, green, red. */
-	rgb[0] = (double) data[2] / 256.;
-	rgb[1] = (double) data[1] / 256.;
-	rgb[2] = (double) data[0] / 256.;
-	
-	/* compute h, s, l data   */
-	l = a[0]*rgb[0] + a[1]*rgb[1] + a[2]*rgb[2];
+      for (unsigned int x = 0; x < page_width; x++) {
+        /* Careful. data color components blue, green, red. */
+        rgb[0] = (double) data[2] / 256.;
+        rgb[1] = (double) data[1] / 256.;
+        rgb[2] = (double) data[0] / 256.;
 
-	h[0] = rgb[0] - l;
-	h[1] = rgb[1] - l;
-	h[2] = rgb[2] - l;
+        /* compute h, s, l data   */
+        l = a[0]*rgb[0] + a[1]*rgb[1] + a[2]*rgb[2];
 
-	/* u is the maximum possible saturation for given h and l. s is a rescaled saturation between 0 and 1 */
-	u = colorumax(h, l, 0, 1);
-	if (u == 0)   s = 0;
-	else          s = 1/u;
+        h[0] = rgb[0] - l;
+        h[1] = rgb[1] - l;
+        h[2] = rgb[2] - l;
 
-	/* Interpolates lightness between light and dark colors. white goes to light, and black goes to dark. */
+        /* u is the maximum possible saturation for given h and l. s is a rescaled saturation between 0 and 1 */
+        u = colorumax(h, l, 0, 1);
+        if (u == 0) {
+          s = 0;
+        } else {
+          s = 1/u;
+        }
+
+        /* Interpolates lightness between light and dark colors. white goes to light, and black goes to dark. */
         t = l;
-	l = t * (l2 - l1) + l1;	
+        l = t * (l2 - l1) + l1;
 
-	if (zathura->global.recolor_keep_hue == true) {
-	  /* adjusting lightness keeping hue of current color. white and black go to grays of same ligtness
-	     as light and dark colors. */  
-	  u = colorumax(h, l, l1, l2);	  
-	  data[2] = (unsigned char)round(255.*(l + s*u * h[0]));
-	  data[1] = (unsigned char)round(255.*(l + s*u * h[1]));
-	  data[0] = (unsigned char)round(255.*(l + s*u * h[2]));
-	} else {
-	  /* Linear interpolation between dark and light with color ligtness as a parameter */
-	  data[2] = (unsigned char)round(255.*(t * (rgb2[0] - rgb1[0]) + rgb1[0]));
-	  data[1] = (unsigned char)round(255.*(t * (rgb2[1] - rgb1[1]) + rgb1[1]));
-	  data[0] = (unsigned char)round(255.*(t * (rgb2[2] - rgb1[2]) + rgb1[2]));
-	}
-	
-	data += 4;
+        if (zathura->global.recolor_keep_hue == true) {
+          /* adjusting lightness keeping hue of current color. white and black go to grays of same ligtness
+             as light and dark colors. */
+          u = colorumax(h, l, l1, l2);
+          data[2] = (unsigned char)round(255.*(l + s*u * h[0]));
+          data[1] = (unsigned char)round(255.*(l + s*u * h[1]));
+          data[0] = (unsigned char)round(255.*(l + s*u * h[2]));
+        } else {
+          /* Linear interpolation between dark and light with color ligtness as a parameter */
+          data[2] = (unsigned char)round(255.*(t * (rgb2[0] - rgb1[0]) + rgb1[0]));
+          data[1] = (unsigned char)round(255.*(t * (rgb2[1] - rgb1[1]) + rgb1[1]));
+          data[0] = (unsigned char)round(255.*(t * (rgb2[2] - rgb1[2]) + rgb1[2]));
+        }
+
+        data += 4;
       }
     }
   }