diff --git a/main.lua b/main.lua
index 8c5fd44..159a145 100644
--- a/main.lua
+++ b/main.lua
@@ -109,6 +109,7 @@ function love.draw()
             lg.line(p3)
         end
     end
+    --[[ 3D tangent lines not working
     do -- Draw tangent line
         local mx = love.mouse.getX()
         local my = love.mouse.getY()/2 - 1/3*H
@@ -122,6 +123,7 @@ function love.draw()
         lg.line(mx-h, y - h*dydx, mx + h, y + h*dydx)
         lg.setColor(255,255,255)
     end
+    ]]
 
     local shader
     shader = love.keyboard.isDown('g') and s1g or s1
@@ -142,7 +144,7 @@ function love.draw()
     lg.draw(canv,W-cw,2*ch)
     lg.setShader(nil)
 
-    lg.setColor(0,0,0,100)
+    lg.setColor(0,0,0,150)
     lg.rectangle('fill',0,0,W,font:getHeight()+love.window.toPixels(5))
     lg.rectangle('fill',0,H/3,W,font:getHeight()+love.window.toPixels(5))
     lg.rectangle('fill',0,2*H/3,W,font:getHeight()+love.window.toPixels(5))
@@ -154,6 +156,9 @@ function love.draw()
     lg.printf("1D_Noise_Shader(x)", 0,5, W-5, 'right')
     lg.printf("2D_Noise_Shader(x,y)", 0,5+H/3, W-5, 'right')
     lg.printf("3D_Noise_Shader(x,y,time)", 0,5+2*H/3, W-5, 'right')
+
+    lg.setColor(20,200,20)
+    lg.printf("hold 'h' for histograms, 'g' for gradients", 5,5, W-5, 'center')
 end
 
 function love.update(dt)