100 Rooms - Level 28

Tap the right button. Tap the table to zoom in. Get glass beakers until your inventory is full. Zoom out.
Press the down button. The clue is on the wall. You'll need to get black, purple, and white colors. Start by filling up the glass beakers: 8 red, 4 blue, and 4 yellow.
To get the purple color: mix red and blue = green, combine it with yellow = skyblue, then red. You will need to get 3 purple colors.
To get the black color: mix red and blue = green, combine it with yellow = skyblue, then purple.
To get the white color: mix purple and black.
Zoom out of the color machine and get two more empty glass beakers. Fill it blue and yellow.
Mix red and blue = green, combine it with yellow = skyblue, add purple = black, lastly pour in white. You'll get a red in a glowing green beaker mixture.
Press the right button and equip your mixture. Tap it on the door.
Door opens. Welcome to level 29.