If LEGO gets exposed to direct or strong indirect sun (like midday sun through a window) on a regular basis, it will eventually get discolored. Discoloration can also happen from artificial light that is too bright and too close to your display. This will especially be visible on white and blue bricks.
LEGO fans have discussed this problem for years, even concluding (correctly) that ultraviolet light can contribute to faster yellowing of colors like white, blue, and old light gray (some of the key colors of Classic Space sets).
Themes that LEGO Made themselves, such as Creator have yellow heads. I think the flesh colored ones are reserved for Minifigures made in an actual characters’ likeness, and the yellow is reserved for generic figures. The yellow head was originally used to represent all races and both genders.
Why are bricks different colors?
These materials are mixed in specific amounts to obtain the desired quality or color of bricks. Burning the brick in extreme temperature is also known to have an effect on the color it acquires. Well-burnt bricks tend to be more reddish, while over burnt bricks are browner. Under burnt bricks are often yellowish and are not as strong.
You might be asking “Why are bricks not all the same colour?”
Mortar of differing strengths or of variable ingredients will dry to a different colour. This can cause an optical illusion making the bricks appear a different colour when in fact they may be consistent with surrounding brickwork.
Efflorescence is a crystaline, salty deposit that occurs on the surfaces of bricks, concrete and other masonry products. It is white, sometimes a brilliant white or an off white colour. When salt loaded water reaches the surface of the brick, air evaporates the water, leaving the salt behind.
The longer they are heated, the darker the color becomes. The standard color for bricks is red because most bricks typically take on a reddish hue when finished. The red hue darkens when they are heated over a longer period of time. Red bricks can have warmer or darker tones mixed in with the overall red coloring.
As a result, you can change color, while retaining the natural variations in tone that give brick a natural look. In fact, instead of coating the brick with a single color, the stain actually mixes with the pre-existing colors within the surface to produce the outcome you want.
Does mortar color have to match brick color?
Keep in mind that the mortar color also needs to match as it can represent a significant portion of the wall (e. g, 18 percent to 20 percent of a modular-sized brick wall), and will have a sizeable effect on the apparent color of the brick.
What causes white stains on brick walls?
White, powdery stains leaching from brick walls are actually crystalline salt deposits. Newly constructed brick walls often contain excessive moisture, which eventually evaporates and transfers salt deposits known as efflorescence onto brick surfaces.
What causes efflorescence on brick walls?
In order for brick efflorescence to become a problem, your brick wall has to meet three conditions: First, your bricks or mortar have to contain water-soluble salts such as sodium sulfates (Na3SO4) or potassium sulfates (K2SO4). Second, water has to be able to get inside of the bricks and dissolve the salts.
You should be wondering “What is the white powder on my brick?”
It often occurs when the flashing, cap stones, rowlocks, chimney crowns, etc.
One answer is, Why it happens. These white patches are salt deposits brought with the building materials which were used (the sand and most often the bricks themselves). When the wall dries after rain, the evaporation of water drives the salts out of the wall and they build up on the surface resulting in these white marks.
How can you tell if Lego is damaged by the Sun?
This would be most visible on white bricks, also blue and light-gray. Just put them next to a brand new piece and you will see if there is any difference. LEGO doesn’t need to be in the dark – it is not that sensitive – but being exposed to direct sunlight can certainly cause damage.