LEGO Color Chart & Hex Reference – Online BrickLink Colors
Browse all official LEGO colors with names, years, and hex codes. Sort by hue. Perfect for builders.
UD5 Toolkit
Browse all official LEGO colors with names, years, and hex codes. Sort by hue. Perfect for builders.
See a cropped or simplified brand logo and guess the company. Hints available, score track. Local fun, no copyright infringement.
Simulate memory page reference strings with FIFO, LRU, and Optimal algorithms. See page fault count. OS concept demo.
Enter a hex color and get its relative luminance per WCAG definition. Understand why this matters for contrast.
Enter L*a*b* values and see the corresponding RGB and hex color. Useful for advanced color manipulation.
Generate a random sequence of button presses that looks like a retro game cheat code. Totally useless, totally fun.
See a random color and type its name. Score based on accuracy. Fun for designers. Local.
Convert hex or RGB to CIELAB L*a*b* values. Understand perceptual lightness and color opponents. Local math.
Explore the RGB color space as a rotatable 3D cube. Pick a color directly from the volume. Drag to rotate. Canvas 3D.
Generate a small logic puzzle grid (like Einstein’s riddle) with clues. Solve in browser or print. Local generation.
Convert any image into colored ASCII art using divs with background colors. Creates a stunning text‑based replica. View & copy HTML.
See how many tabs you have open and estimate memory usage based on navigator object. Fun productivity check.
Create a customizable checkerboard or grid background using pure CSS gradients. Adjust cell size and colors. Copy the code.
Try to draw a perfect circle freehand. Score based on roundness. Fun and addictive. No data sent.
Turn your browser screen into a full‑color flashlight or strobe. Adjust brightness and color. Simple utility.
Create a custom vibration or beep pattern from a short Morse code message. Design unique ringtone ideas.
Random world flags shown; pick the correct country name from four choices. Score and streak. Learn geography.
A replica of the famous Flexbox Froggy game: solve alignment puzzles by writing CSS. Progress saved locally. Fun frontend learning.
Keep a virtual pet alive by feeding, playing, and cleaning. Its state persists in localStorage. Come back or it gets sad.
Get the exact RGB inversion (negative) of any color. Useful for dark mode theming and high‑contrast accessibility checks.
Create a simple tessellation by deforming a square or triangle and repeating it across the canvas. Hypnotic patterns.
Arrange virtual fabric squares or triangles on a grid to preview a quilt pattern. Change colors and sizes. Export layout.
Recreate the target CSS linear gradient by adjusting stops and colors. A unique game for front‑end developers to master gradients.
Mix two or more colors using subtractive (CMYK‑like) blending. See what happens when you combine real paints. Brush effect canvas.
The original arcade Pong recreated in HTML5. Play against AI or local two‑player. Score up to 11 and win. Pure retro fun.
Watch a color sequence and click the same pattern. Gets longer each round. Test and improve your working memory. All local.
Repeat the growing color sequence. How far can you go? Classic memory game with sound and animations.
Control a lunar module and try to land softly on the moon. Manage fuel and thrust. Classic arcade physics. Canvas.
Enjoy classic Tetris in your browser. Rotate, move, and drop tetrominoes. Clear lines and score. Fully local JavaScript.
Create a virtual scratch card with a hidden message or prize. Send the link; recipient scratchs with mouse/touch. Canvas-based.