Pick the right color for your website

Recently, we developed a feature that allow user to change color for their goals. It allows user to recognize different types of goal in their quarter or in the same team easier. However, the hard part is which color should be used?
Bootstrap has 5 colors, which is called Primary (blue), Success (Green), Warning (Orange), Danger (Red) and we are already used these colors to show the progress of user in the progress bar. We have to pick different colors.
So, requirements are:
  • Good for white text.
  • Good with current bootstrap color, harmony with same kind.
  • Playful.
So, why some colors are harmony well together? Basically, before custom picking color, we must understand the color concepts & terminology. These are the basic ones :
  • Hue is color (blue, green, red, etc.).
  • Chroma is the purity of a color (a high chroma has no added black, white or gray).
  • Saturation refers to how strong or weak a color is (high saturation being strong).
  • Value refers to how light or dark a color is (light having a high value).
  • Tones are created by adding gray to a color, making it duller than the original.
  • Shades are created by adding black to a color, making it darker than the original.
  • Tints are created by adding white to a color, making it lighter than the original.

 480px-Munsell-system.svg(Munsell Color System: CC BY-SA 3.0, wikimedia.org)

The rule I follow is:
  • Similar saturation will be harmony well.
  • High saturation will stand out before white.
  • High shade colors stays good with low shade colors.
Analyze Bootstrap colors, I have:
Primary: 006DCC (RGB 0,109,204)
  • Hue: Blue
  • Saturation: Very high
  • Shades: High
Screen Shot 2016-03-13 at 7.51.49 PM
Bootstrap color

Success: 5BB75B (91, 183, 91)

  • Hue: Green
  • Saturation: Medium
  • Shades: High
Warning: FAA732 (250,167, 50)
  • Hue: Orange
  • Saturation: High
  • Shades: Very high
Danger: DA4F49 (218,79,73)
  • Hue: Red
  • Saturation: Medium high
  • Shades: High
Info: 49AFCD (73,175,205)
  • Hue: Blue + Green
  • Saturation: Medium high
  • Shades: High
Exclude the Primary colors, other colors have similar Saturation, which make them harmony well. In order to pick 4 extra colors, there are few options:
1. Reduce shades:
Because Bootstrap color shade is already high, so we can reduce shade of them to make them stand out with Bootstrap color. Notice on the color wheel, the color positions are the same, but the shade is darker. It fits all requirements but the playful.
2. Increase saturation of Bootstrap colors:
Increase the saturation of existing color will create next ones those are harmony. Moreover, different hue with high saturation will create a playful feeling for website. Notice on the color wheel, the color position moved farther from the center. However, the saturation of Bootstrap colors already high so it’s very hard to distinguish with the news colors.
3. Change hue, keep similar saturation:
Similar saturation may make color set seem unify. Notice, the radius of color in the wheel are similar to Bootstrap color. So far, this is the best solution to me. It fits all requirements. However, there is a feeling that it will create too many colors on the website.
We can still do better by changing other components like text colors, progress color and so on, but they are not in the scope of this blog. I just hope this post can provide some useful solution if you have trouble with picking color for your website.

















Install Windows 10 for Raspberry pi 3

March 2016 In, The IoT Community Around The World Witness The Birth Of Raspberry Pi 3. In This Version,   Raspberry Pi 3 Have An Impressive Configuration With A 1.2GHz 64-Bit Quad-Core ARMv8 CPU, 802.11N Wireless LAN, Bluetooth 4.1, Bluetooth Low Energy (BLE). Raspberry becomes a tasty dish for IoT Community.

Note: This guide uses for Raspberry pi 3.

You have to repair:

– A Raspberry pi 3.

– A microSD 8+ GB.

– A computer uses Window 10.

Step 1:. Because Windows 10 IoT core for raspberry 3 just only have the Core Insider Preview version on the newest build, you can not follow the install guide on Raspberrypi.org This is the way for download Windows 10 Core Insider Preview manual.

  1.  The Most Recent Download Insider Preview Image Http://Ms-iot.Github.Io/content/en-US/win10/GetStartedManually.HtmL
  2.  Click the desired image under the “Windows 10 IoT Core Insider Preview”.
  3.  Find the downloaded .ISO and double click on it.
  4. Double click the Windows Installer Package (.MSI) and follow the installation steps.

Step 2: repair your microSD card.

  1. Click  Http://Ms-iot.Github.Io/content/en-US/GetStarted.Htm  And Download Windows 10 IoT Core Dashboard-> Install.
  2. Click “Set up a new device”. Once there, select “Custom” from the “Device type” drop down. Click the “Browse” button to find your image (.ffu)
  3. Navigate to “C: \ Program Files (x86) \ Microsoft IoT \ FFU \ DeviceType” and select Flash.ffu.
  4. Click “Install”. Note that you must have a compliant SD card to successfully flash. We recommend a Class 10 SD card with a size of at least 8 GB or more. Once done flashing, you can remove the SD card and plug it into your device.

Step 3:. Put your microSD card into Raspberry pi 3 and connect with a monitor Turn it on and enjoy.


Common Errors:

error:. error executing partition setup script win 10 IoT The reason is using NOOBS.

error:. can not boot OS image Usually, the reason is install the wrong build of OS, may be a OS for Raspberry pi 2.

“Install Windows 10 for Raspberry pi 3″の続きを読む









古河マラソン以降、フルマラソンへの気持ちが向かず、一時は辞めようかということも考えるようになりました。自分が誘ってフルマラソンを走るようになった人には申し訳がなかったのですが、フルマラソン、なんでフルマラソンを走っているんだろう?と、そもそもの目的も見失いかけていたのです。Why? Why? Why?



走ることを決意したものの、Why? なぜフルマラソンを走るのだろう?ということは忘れたままでした。

It’s time to start


















Which Wireless Technology for Smart home?

The IoT revolution has never been this close. Almost every big technology corporation has joined the race. And one of the most attractive trend is the Smart House. It implies the fact that you can connect all of the devices and control, track them easily from . distance Along with the development of transmitting technology, the speed is getting faster and the bandwidth is getting bigger, we now must answer the question: Which technology suits our Smart house the most?

As well as the other electronic systems, devices within a smart house need a protocol to communicate with each others. It is simply a group of common behavior in an information channel like human’s language or the voice of a bird. Every protocol I mention below all have their pros and cons. They can give you an idea about the technique you should use in your own smart devices. This article is just for reference and will not go into details about technology.


X10 is a protocol for communication among electronic devices used for home automation (domotics) .It primarily uses power line wiring for signaling and control, where the signals involve brief radio frequency bursts representing digital information.A wireless radio based protocol transport is also defined ( wiki).  It IS the first Protocol for Automatic Devices Appeared in 1970s, it the uses Wires and not BE Seen much lately.


Insteon is a home automation (aka domotics) technology that enables light switches, lights, thermostats, leak sensors, remote controls, motion sensors, and other electrically powered devices to interoperate through power lines, radio frequency (RF) communications, or both (Wiki ). It  IS a wired or Wireless Protocol. In CAN BE linked with the X10.


Z-wave is a wireless protocol working in the frequency of 908.42 MHz. This is a new technology and has been developed rapidly in the last few years. The Z-wave alliance had produced many different kind of devices that can connect with each others. It gives users more choices. The salient feature of Z-wave is the web-alike system. It helps the system to have maximum expanding potential with low cost of energy, suitable for devices that use batteries.


ZigBee is developed based on 802.15.4 wireless standard. As well as Z-wave, ZigBee had developed rapidly in recent years. This is an open source technology and there are many company using ZigBee technology. ZigBee costs very few energy as well as using web-alike system to expand and communicate faster. However, there are users complaination about the hard-to-connect problem between ZigBee devices.


Ofcourse, wifi is very popular now and there are many smart devices using WiFi technology. But it has a weakness, that is network problem. When there are too many devices using wifi in a house will slow down its speed. And wifi costs a lot of energy which makes it unsuitable for batteries-use devices like door lock or door bell.


BLE is Bluetooth Low Energy, a new Bluetooth standard which helps users economize their cost of energy. It has become a trend in recent years and received big investments from big enterprises. There are more and more devices using BLE appeared because of its energy saving and transmitting ability up to 100m in empty space, wide bandwidth which is suitable for devices within a house.

Finally, I hope this article can give you an overview about the techniques that being used in smart houses. And I hope you can choose for yourself the most suitable technique.



Life is short.





Life is short.








kitano少し報告が遅くなりましたが、2016年2月10日に新会社 株式会社zabutonを設立しました。改まった気持ちに浸っていたいところではありますが、現在進めている第一弾のアイデアのリリースに向けてチームメンバーの一員として絶賛邁進中でございます。